VSL 3 utilizes a synergistic combination of diverse strains of bacteria including: Streptococcus thermophilus, Bifidobacteria longum, Bifidobacteria infantis, Bifidobacteria breve, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus paracasei and Lactobacillus delbrueckii subsp.

Clinical studies using VSL 3 and published in notable journals, such as Gut, Gastroenterology and the American Journal of Gastroenterology have indicated that it colonizes the GI tract with beneficial bacteria, and in doing so, forms an intestinal barrier, which may help protect the GI tract and promote the absorption of nutrients.

VSL 3 is one of the few probiotic preparations supported by Level 1 double-blind, placebo-controlled scientific data, and has been the subject of a collection of more than 80 studies that have demonstrated its efficacy, specifically in the dietary management of IBS, Ulcerative Colitis and Ileal Pouch. It is the only probiotic recognized as an effective tool in the dietary management of pouchitis by the American College of Gastroenterology2 and by the Cochrane Review3 for the treatment and prevention of pouchtis after ileal pouch-anal anastamosis for chronic ulcerative colitis.

Radiation-induced enteritis: Enteritis and colitis characterized by diarrhea are severe complications of radiotherapy that may lead to the development of bacterial overgrowth in patients who have cancer[ 38 ].

Two trials have addressed the utility of adding VSL 3 to radiation-induced enteritis therapy. They demonstrated that VSL 3 was a great approach to prevent the occurrence and reduce the severity of radiation-induced enteritis with good tolerance[ 39 , 40 ]. One trial showed that more patients treated with placebo had radiation-induced enteritis The up-regulation of the innate immune reaction against invasive microbiota is probably one of the important mechanisms underlying the therapeutic effect of VSL 3 in patients with radiation-induced enteritis[ 39 ].

Chemotherapy-induced diarrhea: Chemotherapy can cause diarrhea, which worsens the quality of life of cancer patients. An animal study demonstrated that VSL 3 with irinotecan was able to prevent severe diarrhea following chemotherapy and weight loss in female rats[ 42 ].

However, it is still uncertain whether VSL 3 is effective in clinical application. Rotavirus diarrhea: Rotavirus is one of the main causes of severe gastroenteritis in children[ 43 ]. It is transmitted directly through the fecal-oral route, and the main symptom of rotavirus infection is diarrhea, which is usually accompanied by abdominal pain, vomiting, and fever. One randomized controlled trial RCT indicated that the administration of VSL 3 resulted in better overall recovery rates and reduced frequency of oral rehydration salts and intravenous fluid use in children with acute rotavirus diarrhea[ 44 ].

Other diarrhea: Gastrointestinal complications are common complications in enterally-fed critically ill patients. They will prolong hospitalization and increase the mortality of patients[ 45 ].

A pilot trial indicated that VSL 3 had benefits in reducing the frequency of liquid and loose stool and stool weight, further minimizing diarrhea in enterally-fed critically ill patients[ 46 ]. A randomized phase II trial demonstrated that VSL 3 had no effect on the incidence of all-grade diarrhea adverse events and the quality of life of advanced non-small-cell lung cancer patients treated with dacomitinib, which is a tyrosine kinase inhibitor[ 47 , 48 ].

An improvement may have been induced by VSL 3 in tissue functions, but this requires confirmation. IBS is a common chronic gastrointestinal functional disease characterized by sudden changes of two major symptoms: Constipation and diarrhea. The pathogenesis of IBS remains unclear, but an improvement of colon dysmotility and visceral hypersensitivity may play an important role in treating it[ 49 ].

It demonstrated that VSL 3 might relieve abdominal bloating, especially in patients with higher bloating scores, but VSL 3 had no significant effect on colonic transit and bowel function[ 50 ].

Another study showed that VSL 3 was able to dampen clinical symptoms by improving the mechanical distensions of the colonic wall in patients with diarrhea-predominant IBS[ 49 ]. In addition, another trial suggested that VSL 3 was able to improve IBS symptoms significantly by increasing salivary morning melatonin, particularly in males and individuals with normal circadian rhythm[ 52 ]. Furthermore, VSL 3 was superior to placebo in improving symptoms including abdominal pain and abdominal bloating in children with IBS[ 53 ].

But the mechanism has not been clearly studied. In a rat model of IBS, one study demonstrated that VSL 3 could reverse visceral hyperalgesia and allodynia and reset gene expression related to pain and inflammation such as tryptophan hydroxylase 1 [ TPH1 ] [ 54 ].

Also, VSL 3 treatment decreased visceral hypersensitivity probably by decreasing the number of mast cells in the colon and decreasing protease-activated receptor 2 and transient receptor potential vanilloid type 1 expression in dorsal root ganglia in an experimental rat model of IBS[ 55 ]. Furthermore, nitric oxide NO might participate in the beneficial effect of VSL 3 to some extent[ 56 ].

Moreover, patients with IBS and chronic bacterial prostatitis CBP had a significantly greater number of male accessory gland infections compared with patients with CBP alone[ 58 ]. Besides, the second trial demonstrated that long-term treatment with VSL 3 and rifaximin was effective in reducing the evolution of chronic prostatitis into more complicated infections of male accessory glands, such as chronic microbial prostate-vesiculitis or prostate-vesiculo-epididymitis PVE , in infertile patients with IBS plus cured CBP[ 60 ].

The etiology and pathogenesis of IBD are not quite clear at present. It is currently thought that possible factors include environmental factors, genetic susceptibility, infection factors, and a dysregulated immune system. An improper immune response to the intestinal microbiota probably contributes to the occurrence of IBD in genetically susceptible hosts. Dietary factors among environmental factors might influence immune function and could also be some of the risk factors for the occurrence of IBD[ 61 , 62 ].

One study indicated that milk and fried food were associated with an increased risk of IBD[ 63 ]. The treatment of IBD may be associated with multiple mechanisms, such as by altering the intestinal microbial composition to improve IBF. UC: UC is a kind of chronic inflammatory colonic disease. In a systemic review, Eubacterium rectale and Akkermansia were decreased in all three studies, and Escherichia coli E. Traditionally, UC can be treated or maintained with immunomodulatory or anti-inflammatory drugs, such as 5-aminosalicylic acid 5-ASA [ 65 ].

Also, VSL 3 has been reported to have a maintenance effect. One trial enrolled 20 patients with UC in remission who were treated with VSL 3 and identified that 15 patients were still in remission. The underlying mechanism is not completely understood, but it was shown that VSL 3 was able to induce a significant increase of protective bacterial strains Streptococcus salivarius subspecies thermophilus , Lactobacillus , and Bifidobacteria compared to their basal levels in feces of patients.

Furthermore, VSL 3 could colonize the intestine and decrease fecal pH from the 20th day of treatment period and keep it stable[ 66 ]. In two trials, VSL 3 was both capable of reducing the UC disease activity index DAI scores and ameliorating clinical symptoms significantly compared with placebo[ 67 , 68 ].

One trial indicated that there were Besides, VSL 3 and the traditional drugs seem to have a synergistic action. The mechanism is unclear, but it was possible that VSL 3 could increase the anti-inflammatory action of 5-ASA, which could reduce free radical production and then leukotriene and IL-1 production[ 67 , 69 ].

One trial also demonstrated that the combination therapy of low-dose balsalazide and VSL 3 was more effective than balsalazide or mesalazine alone in obtaining the remission of acute mild-to-moderate UC[ 70 ]. A longer treatment with VSL 3 may provide more of an improvement. It was shown that VSL 3 could improve more parameters such as stool frequency significantly in a wk trial than in an 8-wk trial[ 67 , 68 ].

Two bacterial components S. Then, the effect of alkaline sphingomyelinase was investigated in 15 UC patients treated with VSL 3 for 5 wk. The results clarified that VSL 3 up-regulated mucosal alkaline sphingomyelinase activity and improved UC[ 72 ]. VSL 3 also has a beneficial effect in children with UC. Except for the role in maintaining remission, another pilot study demonstrated that therapy with VSL 3 resulted in a remission of the disease in children with mild-to-moderate acute UC[ 74 ].

In addition, the recommended level for VSL 3 use in maintaining the remission of UC was an A rating and the recommended level in inducing remission was a B rating[ 41 ]. One study demonstrated that VSL 3 0. However, one study showed that VSL 3 0.

It revealed that VSL 3 had a tendency to decrease histological inflammation but not change colon inflammatory characteristics. Furthermore, the increase of Bifidobacteria was not enough to repair the intestinal barrier impairment[ 77 ]. The above results are not exactly consistent, and the negative result may be related to the sex of mice and the induced pattern of DSS colitis.

The dose, mode of administration, and treatment course of VSL 3 also impact the result to some extent. In addition, the anti-inflammatory effect is still the main therapeutic mechanism of VSL 3 in DSS-induced rat colitis. TLR9 signaling and myeloid differentiation marker 88 MyD88 also played an important role in mediating the anti-inflammatory effect of VSL 3[ 26 ].

CD: CD is a kind of patchy transmural inflammation affecting any part of the intestinal tract. The pathogenesis of CD is associated with the defect of mucosal innate immunity accompanied by the failure of clearing bacteria and bacterial debris, which leads to an improper adaptive immune response to the intestinal commensal bacteria.

In a systemic review, Christensenellaceae and Coriobacteriaceae in all three studies and Faecalibacterium prausnitzii in six of eleven studies were decreased compared with controls, and Actinomyces , Veillonella , and E. Some patients with CD will require an operation, but surgery cannot cure it, and post-operative recurrence is common[ 84 ]. This finding indicated that the exposure time of VSL 3 is closely associated with its therapeutic effect. Moreover, several studies elucidated the protective effect of VSL 3 in 2,4,6-trinitrobenzene sulfonic acid TNBS -induced colitis from different mechanisms.

For instance, VSL 3 was proven to reduce the up-regulation of gene clusters associated with mast cells in TNBS colitis by suppressing chemokine gene expression[ 31 ]. Besides, it was shown that VSL 3 resulted in lower macroscopic and microscopic damage in the proximal colon and lower macrophage infiltration in rat acute TNBS-induced colitis[ 88 ]. Pouchitis: Pouchitis is a nonspecific inflammation of the ileal reservoir, which is known as a long-term complication after ileal pouch anal anastomosis IPAA surgery.

It is characterized clinically by abdominal pain, bloating, and increased stool frequency[ 89 ]. The recommended level was an A rating[ 41 ]. In addition, an open-label trial clarified that high-dose VSL 3 3.

The recommended level was a C rating[ 41 ]. It suggested that the recommended level of VSL 3 in inducing the remission of pouchitis was not as good as that in preventing and maintaining the remission of pouchitis. Although VSL 3 was effective in the therapy of chronic pouchitis, an open-label trial indicated that most patients with antibiotic-dependent pouchitis were not capable of accessing the long-term therapy of VSL 3, mainly due to recurrent symptoms[ 93 ].

Microscopic colitis is a chronic inflammatory disease of the intestine characterized by chronic diarrhea with a normal endoscopic appearance of the colon[ 94 ]. A randomized, open-label trial demonstrated that VSL 3 had a benefit in inducing and maintaining short-term clinical remission of active microscopic colitis compared with mesalamine.

Furthermore, a significant decrease of iNOS scores in the VSL 3 group suggested a decrease in the inflammatory status of the disease[ 95 ]. The trial had limitations probably due to a small sample size. Diverticulitis is an inflammation related to the diverticula of the colon. An open, pilot clinical trial demonstrated that a combination therapy of VSL 3 and balsalazide had a better effect than VSL 3 treatment alone in preventing relapse and maintaining the remission of uncomplicated diverticulitis[ 96 ].

Familial adenomatous polyposis FAP is an inherited autosomal dominant disorder characterized by high proliferation of epithelial cells in the pouch mucosa[ 97 ]. A randomized, pilot trial demonstrated that sulindac therapy alone and treatment with VSL 3 and inulin tended to reduce cell proliferation and increase glutathione S-transferase GST enzyme activity in patients with FAP and IPAA, while the combination treatment with sulindac, inulin, and VSL 3 had no effect[ 98 ].

However, the trial had such a small number of patients enrolled that the conclusion might not be stable or reliable. Colitis is a chronic inflammatory colonic disease, and patients have a higher risk of suffering from colorectal cancer CRC compared with healthy people. It was reported that the risk of CRC had a 2. The combination of metformin and VSL 3 was able to decrease inflammation and tumor progression by inhibiting macrophage infiltration, and the positive effect of VSL 3 against murine UC-associated carcinogenesis was achieved by adjusting the proportion of beneficial and harmful bacteria in feces and the intestinal mucosa[ , ].

One study showed that VSL 3 could retard the development of colonic inflammation to dysplasia and cancer, accompanied by an increase in antiangiogenic factor vitamin D receptor VDR in a rat model of colitis-associated CRC[ ].

However, in terms of murine colitis-associated CRC, two studies showed contrasting results. VSL 3 produced the effect of enhancing tumorigenesis probably by inducing the depletion of protective commensal bacteria. However, the effect was not related to inflammatory cytokines[ ].

The different results may be associated with the type of mice and the induced pattern of murine CRC used in the two studies. The dose, mode of administration, and treatment course of VSL 3 may also have impacted the results. VSL 3 was administered daily by orogastric gavage using a ball tip gavage needle at a dose of 1. There is a close relationship between the liver and intestine tract. The metabolism of bile acid is tightly connected with the intestinal microbiota.

The probiotic mixture VSL 3 was shown to modulate intestinal microbiota, thus down-regulating the intestinal-liver FXR-FGF15 axis to induce ileal bile acid deconjugation, fecal bile acid excretion, and the synthesis of bile acid in the liver[ 17 ]. Hence, VSL 3 may have a potential for treatment of chronic liver diseases and their complications.

Non-alcoholic fatty liver disease NAFLD is an increasing problem worldwide, and is now one of the leading causes of chronic liver diseases in Western countries[ ]. It encompasses a spectrum of histopathological changes from simple liver steatosis to steatohepatitis, advanced fibrosis, and cirrhosis, and NAFLD may be caused by intestinal dysbiosis, which increases intestinal permeability to bacterial products and harmful substances[ , ].

Intestinal dysbiosis can also cause intestinal dysmotility, inflammation, and other immune responses that may contribute to hepatic inflammation and fibrosis[ ].

GLP-1 could stimulate the endocrine pancreas, thus improving insulin sensitivity in order to improve glucose and fat metabolism[ ]. Besides, it was suggested that the administration of VSL 3, by increasing GLP-1, was able to regulate the metabolic flux of muscle mitochondria, make valine be completely degraded, and finally produce succinyl-coenzyme A, the intermediate product of citric acid cycle, which is used for energy metabolism[ ].

Trials assessing the effect of VSL 3 in patients with non-alcoholic fatty liver disease. It acts by improving liver histology and liver insulin resistance, and decreasing the level of serum alanine aminotransferase[ ]. TNF-regulated kinase Jun N-terminal kinase could promote insulin resistance by increasing the serine phosphorylation of insulin receptor substrate-1[ ].

The increase of hepatic natural kill T cell expression stimulated by lipids extracted from VSL 3 also contributed to the improvement of hepatic insulin resistance[ , ]. Effects of VSL 3 on insulin sensitivity.

GLP-1 can stimulate the pancreas and ameliorate insulin sensitivity to improve glucose and fat metabolism[ ]. The increase of hepatic natural kill T NKT cells caused by VSL 3 also plays a significant role in the improvement of hepatic insulin sensitivity[ , ].

Intestinal barrier dysfunction may be related to endotoxemia and eventually cause hepatic inflammation and the development of alcoholic liver disease ALD [ ]. One trial indicated that VSL 3 could mitigate liver damage in patients with alcoholic liver cirrhosis by decreasing the plasma levels of malondialdehyde, 4-hydroxynonenal, and S-nitrosothiols. Besides, one study demonstrated that VSL 3 was as effective as glutamine in rats with experimental acute ALD, and the combination therapy was more effective.

The action mechanism mainly proceeded by reducing intestinal permeability[ ]. Impaired IBF, bacterial overgrowth, and disturbance of local immunity contribute to bacterial translocation BT in cirrhosis; BT is one of the major causes of many complications of cirrhosis[ , ]. Gram-negative enteric bacilli, such as E. However, no differences could be observed in the plasma level of IL-6 or NO[ ].

Another trial observed a significant decrease in plasma aldosterone levels induced by VSL 3, but the changes in the other measured parameters, including the stool microbiota, were not significant[ ]. Apart from the above-mentioned plasma component changes, VSL 3 treatment induced an increase in the plasma levels of albumin and hemoglobin, which might lead to lower model for end-stage liver disease scores in patients with decompensated liver cirrhosis[ ].

The effect of VSL 3 was also proven in a rat model of biliary cirrhosis with portal hypertension. VSL 3 prevented endothelial dysfunction by improving vascular oxidative stress reducing BT and the local angiotensin system[ ]. Patients with liver cirrhosis could cause systemic inflammation, which may be associated with hepatic encephalopathy HE [ ]. MHE improved in This change is probably related to the significant decrease in the number of patients with MHE and the small intestinal bacterial overgrowth in the VSL 3 group[ ].

The secondary prophylaxis efficacy of VSL 3 was investigated in another trial in patients with cirrhosis who have recovered from an episode of HE. Fewer patients hospitalized for HE were observed in the VSL 3 group compared with the placebo group The results also indicated that VSL 3 improved systemic inflammatory response syndrome and model for end-stage liver disease scores, and decreased plasma indole, renin, aldosterone, and brain natriuretic peptide levels significantly[ ].

VSL 3 administration in chronic liver diseases still has its own limitations. We need further studies to clarify its therapeutic effect in portal hypertension and its complications. VSL 3 has been shown to significantly decrease body and fat mass during a high-fat diet compared with placebo[ , ]. At present, there are no definite clinical trials about the effect of VSL 3 on diabetes mellitus.

However, the efficacy of VSL 3 on diabetes has been researched in obesity and non-obesity murine models. Increasing evidence supports the idea that impaired IBF promotes the access of infected pathogens to mucosal immune elements, which may eventually lead to diabetogenic immune responses and insulin resistance[ ].

Two studies demonstrated that oral administration of VSL 3 was able to prevent spontaneous autoimmune diabetes in non-obese diabetic NOD mice[ , ]. VSL 3 treatment increased the release of protolerogenic components of the inflammatory corpuscles, such as indoleamine 2,3-dioxygenase IDO and IL These changes regulate intestinal immunity in VSL 3-treated NOD mice by promoting the differentiation of tolerant dendritic cells and reducing the differentiation of Th1 and T-helper 17 Th17 cells in the intestinal mucosa[ ].

Besides, IDO inhibited T cell proliferation by limiting the local tryptophan concentration directly, thus reducing Th1 and Th17 cell differentiation[ ]. In addition, VSL 3 treatment increased protolerogenic species, and decreased the relative abundance of species, such as Bacteroidetes S , in NOD mice[ ]. However, one study showed that VSL 3 could not delay diabetes probably because it colonized the intestine poorly and could not overcome the effect of diabetogenic microbiota[ ].

The result contradicts previous studies and the reasons for this need to be further studied. Moreover, one study demonstrated that VSL 3 was able to prevent diabetes in high fat diet-induced obesity mice by inhibiting weight gain and insulin resistance. Increased transcript levels of free fatty acid receptor 3 Ffar3 were observed in VSL 3-treated murine intestine. It is known that VSL 3 has the capacity to regulate immune responses, so it has been considered to treat allergic diseases.

There have not been definite conclusions about the efficacy of VSL 3 on allergic diseases in clinical trials, but a potential effect of VSL 3 has been shown in animal studies. Several studies demonstrated that the oral administration of VSL 3 had a beneficial effect in ameliorating anaphylactic symptoms in murine food allergy induced by shrimp tropomyosin ST or peanut by inhibiting T-helper 2 Th2 immune reactions[ - ].

The administration of VSL 3 1. Two studies showed that VSL 3 was able to improve some types of nervous systemic disorders and related brain mechanisms through the gut-brain axis when dysbiosis caused by a cafeteria diet or the ageing process occurred in rats[ , ].

VSL 3 was proven to prevent diet-induced memory deficits on the place task but had no effect on anxiety-like behaviors on the elevated plus maze EPM in rats[ ]. Furthermore, one study indicated that VSL 3 improved the age-related deficits in long-term potentiation in aged rats.

The effect was accompanied by a decrease of microglial activation markers and an increase of brain-derived neurotrophic factor and synapsin. The effects above might be due to the increase in the amounts of Bacteroidetes and Actinobacteria caused by VSL 3[ ].

One study showed that the effects of VSL 3 on the nervous system are independent of the changes in the intestinal microbiota in rats. VSL 3 could significantly improve sickness behaviors and brain dysfunction, probably by decreasing microglial activation and brain inflammatory monocyte infiltration in bile duct ligation mice with liver inflammation[ ].

Furthermore, one study demonstrated that the post-injury treatment of VSL 3 improved locomotor recovery after murine spinal cord injury and activated neuroprotective mucosal immune cells[ ]. Atherosclerosis AS is a chronic disease that might be associated with the bacteria from the oral cavity and even the gut[ ].

They demonstrated that VSL 3 had a beneficial effect on AS and perhaps worked by significantly reducing the development of atherosclerotic or aortic plaques and biomarkers of vascular inflammation. Vascular cell adhesion molecules and intercellular adhesion molecules were shown to be reduced by VSL 3 in both two studies[ , ].

One study indicated that VSL 3 2. The reason for this is not clear. Diseases of the female reproductive system include various kinds of diseases, such as gynecological inflammation, gynecological tumor, menstrual disorder, and infertility.

Breast milk provides nutritious substances for infant growth and development, and it also provides several altered beneficial microbiota including Staphylococci , Streptococci , Lactobacilli , and Bifidobacteria [ , ]. These beneficial bacteria in maternal milk will transfer from mother to infant and colonize the infant intestine during lactation[ ]. The balance of vaginal microbiota is important during pregnancy, and abnormal vaginal communities such as bacterial vaginosis may be associated with preterm delivery and perinatal complications[ ].

One trial showed the potential implications of VSL 3 in preventing preterm birth via an anti-inflammatory effect on vaginal immunity in healthy pregnant women. The consumption of VSL 3 led to a decrease of the pro-inflammatory chemokine Eotaxin. There were no significant alterations in the amount of the principal vaginal bacteria in women orally administered with VSL 3. However, VSL 3 played a potential role in counteracting the decrease in Bifidobacteria and the increase in Atopobium.

VSL 3 was also capable of modulating the Lactobacillus population, which was associated with the decrease of L. One study indicated that VSL 3 was able to survive and stay stable in a continuous culture system simulating the vaginal environment and inhibit the vaginal vault pathogen Gardnerella vaginalis [ ].

There are almost no serious side effects related to the use of VSL 3 in most diseases. Among these side effects, only very few are intolerable. A meta-analysis showed that 33 patients experienced mild side effects mainly bloating out of UC patients treated with VSL 3[ ]. One patient was reported to experience abdominal cramps, vomiting, and diarrhea out of 20 patients with pouchitis who received VSL 3[ 90 ].

Finally, of the 31 pouchitis patients treated with VSL 3, two experienced intolerable side effects: One experienced bloody bowel movements and the other experienced severe constipation, bloating, and gas[ 93 ].

The use of VSL 3 also has some limits. VSL 3 contains only eight bacterial strains, and the intestinal microecosystem of each patient is complex, so these strains may not be suitable for all patients.

Achieving the one-to-one treatment of formula probiotics and individuals is difficult. The results mentioned above of VSL 3 in the treatment of various diseases are not exactly consistent, which may have been caused by different sources of VSL 3. One study indicated that proteomic analyses showed differences in protein abundances, identities, and origins of VSL 3 from different sites[ ].

Therefore, we suggest that the protein abundances should be identified through proteomic analyses in the clinical and basic studies of VSL 3 in the future.

In the past, it has been reported that VSL 3 has a profound effect on digestive systemic disorders, especially gastrointestinal disorders. Apart from this, many studies demonstrated that VSL 3 has a beneficial effect on obesity and diabetes, allergic diseases, nervous systemic diseases, AS, bone diseases, and female reproductive systemic diseases.

In most cases, the use of VSL 3 is safe and well-tolerated, but more precise mechanisms and effects of VSL 3 still need to be studied. To achieve one-to-one individualized treatment, we need to prepare exclusive probiotics according to the real-time monitoring of patients' intestinal microbiota.

However, the current detection technology is not accurate enough. The study of the intestinal microbiota is challenging since most cannot be cultivated[ 10 ]. Thus, the solutions to the above problems will hopefully provide a new direction for precise medicine in the future. Conflict-of-interest statement: The authors disclose no potential competing interests. Manuscript source: Invited manuscript. Peer-review started: December 30, First decision: February 19, Article in press: April 8, Specialty type: Medicine, research and experimental.

VSL 3 capsules: Lactic acid bacteria, microcrystalline cellulose, stearic acid, magnesium stearate, hydroxylpropyl-methylcellulose HPMC vegetarian capsule , silicon dioxide, non-fat dry milk. They are gluten and dairy free although manufactured using dairy which is then removed so may contain dairy traces. Sprinkle sachet on any cold food or in a non-fizzy cold drink. The recommended daily intake is one to two sachets or capsules a day. Other amounts may be recommended by your doctor or therapist.

VSL 3 says that it has chosen bacteria strains that survive the strong, acidic conditions of the stomach and stick to the gut wall so they can colonise in the intestine.

They also say that number of bacteria in each dose billion make it effective. However, it is now no longer available for prescription in the UK following a review 2 which said there was 'low quality evidence' of the benefits.

Concerns were raised about the size of the studies and that 'the evidence did not sufficiently demonstrate that the products are clinically effective'. There have also been several studies into VSL 3 and ulcerative colitis. One study has been carried out into VSL 3 and microscopic colitis 7. VSL 3 says each batch is quality-tested to confirm numbers of colony-forming units and to ensure the absence of contaminants.

During this testing they also test the integrity of the strains to ensure the strains in the product are the same as the strains advertised.

If unopened and stored under refrigeration, the product is guaranteed until the 'best before' date, which is 24 months from manufacture. These bodies issue guidelines around what probiotic companies can say in relation to their product and health claims they can make.

Even if a probiotic has medical evidence to support its use for a certain condition they cannot publicise this unless they go through strict medical testing - a very expensive and lengthy process.

This is why you will often find that probiotic companies do not mention specific health conditions on their website and marketing material. Guidelines have also been issued to say that the term probiotic may no longer be used in the promotion of supplements by the companies. The Advertising Standards Authority also has oversight regarding claims made and any complaints arising. Why not sign up to our mailing list and receive regular articles and tips about IBD to your inbox.

Why not sign up to our mailing list and receive regular articles and tips about IBD to your inbox? Probiotic VSL 3 for ulcerative colitis and Crohn's disease.

What's in VSL 3?