Gastrointestinal System - Probiotics

Summary of Recommendations and Evidence


 
This Summary of Recommendations and Evidence synthesizes the Key Practice Point(s) for each Practice Question (PQ) in this Knowledge Pathway. It is organized by the Nutrition Care Process and contains statements or recommendations that have been graded using either the PEN or GRADE approaches to critical appraisal. For additional information on the evidence and references, see the PQs in this Knowledge Pathway
 
Content 
INTERVENTION
  1. Probiotics and IBS 
  2. Probiotics and the Prevention of Acute Pouchitis in Adults
  3. Probiotics and Treatment of Acute and Chronic Pouchitis 

MONITORING/EVALUATION

  1. Safety/Cautions with Probiotics


 

1. Probiotics and IBS
Recommendation
Probiotic Products
There are many probiotic products available in different doses and variable bacterial strains. Individuals with IBS who choose to try probiotics should be aware that some products contain other ingredients that may increase IBS symptoms (e.g. dietary fibre: oats; FODMAPs: FOS, inulin, lactose, fructose, sorbitol and xylitol).

Recommendations for specific probiotic products were not possible because of inconsistency in outcome benefits across studies on the same probiotic or only one study assessing a probiotic. There is currently inadequate evidence to recommend any specific probiotic product and, independent of IBS-subtype (constipation or diarrhea or mixed predominant IBS), improvement in all symptoms is unlikely. 

Safety
In general, taking probiotics for IBS is considered safe, and if an individual finds four weeks of use of a probiotic beneficial, they can continue to take it. However, the long-term effects are not known, because the longest period of taking probiotics in the 35 RCTs was six months, with the majority of the study intervention durations lasting less than eight weeks. For individuals with co-morbidities that may modulate immune function, health care professionals should use these recommendations, assessing each individual on a case by case basis. Probiotics are often expensive, so individuals may wish to weigh benefits against ongoing cost. Probiotic-fermented milks and yogurts are a good source of calcium. Health care professionals can use these guidelines to inform individuals with IBS about the limited benefits of probiotics and the potential for a placebo response, which is known to be high in IBS clinical trials.

Evidence Summary

Evidence analysis from a systematic review conducted by the British Dietetic Association (BDA) on probiotics and IBS (see Comments re: use of this systematic review within the PEN System®) indicates that:
  • Out of 35 RCTs, no strain- and dose-specific probiotic demonstrated efficacy from more than two RCTs. Therefore, no specific recommendations can be made regarding the effect of probiotics on IBS symptoms. 
    Grade of Evidence C
Clinical practice recommendations outlined in the BDA probiotics review include:
  • Advise that probiotics are unlikely to provide substantial benefit to IBS symptoms. However, individuals choosing to try probiotics are advised to select one product at a time and monitor the effects. They should try it for a minimum of four weeks at the dose recommended by the manufacturer.
    Grade of Evidence B 
  • Taking a probiotic product is considered safe in IBS. 
    Grade of Evidence B

 

2. Probiotics and the Prevention of Acute Pouchitis in Adults
Recommendation
The benefits of taking probiotics for the prevention of pouchitis in adults with ileal pouch-anal anastomosis (IPAA) are uncertain and are not recommended due to very limited and low quality evidence. Adverse events of taking probiotics (i.e. VSL#3, Bifidobacterium longum BB-536 or Clostridium butyricum) were generally not reported in the studies.

Evidence Summary

Results of a Cochrane systematic review of four RCTs indicated that for those without active pouchitis and who underwent IPAA for ulcerative colitis, taking probiotics for six to 24 months did not result in a decrease in bouts of acute pouchitis compared to placebo or no treatment as defined by a change in the Pouchitis Disease Activity Index (PDAI) score. The probiotic VSL#3 was taken in two of the trials, while Bifidobacterium longum BB-536 was used in one trial and Clostridium butyricum MIYAIRI3 in the other trial. Adverse events were not reported. Results are uncertain due to the limited number of probiotics used, the small number of study participants and selection and reporting biases.
Grade of Evidence C
 
Remarks
The primary outcome for prevention of pouchitis was the number of pouchitis episodes after IPAA in adults with ulcerative colitis.  

VSL#3® is a commercially available oral probiotic formulation containing eight different strains of bacteria (L. acidophilus, L. delbrueckii ssp. bulgaricus, L. plantarum, L.casei, B. infantis, B. longum, B. breve and S. salvarius ssp. thermophilus).

 

Additional Remarks

Active pouchitis (acute or chronic) can include symptoms: diarrhea, increased stool frequency, abdominal cramping, fecal urgency, tenesmus (i.e. feeling the need to constantly pass stool) and incontinence. 
 
3. Probiotics and Treatment of Acute and Chronic Pouchitis
Recommendation
For the treatment of acute and chronic pouchitis, it is uncertain if probiotics improve symptoms or maintain remission compared to the placebo or no treatment groups. This is primarily due to the small number of studies with few participants and different types of probiotics used. Lactobacillus GG has not been associated with adverse effects; VSL#3 may have mild adverse effects (i.e. abdominal cramps, vomiting and diarrhea).

Evidence Summary

Acute Pouchitis
Results of a Cochrane review identified one RCT (n=40), which showed no difference in clinical improvement (Pouchitis Disease Activity Index (PDAI) score) of the probiotic group (Lactobaccillus GG, two capsules twice per day) compared to the placebo group. Only 10% of the Lactobacillus GG participants compared to 0% of the placebo group showed a clinical improvement. While the probiotics were well tolerated, results are limited by only one study with unclear risk of bias and the small number of participants. 

Chronic Pouchitis
Results of a Cochrane review identified two RCTS (n=76) of VSL#3 (3-6 g/day or one to two packets/day for nine to 12 months), which showed that 85% maintained remission (as defined by a PDAI score of >2 at nine to 12 months) compared to 3% of placebo participants. Adverse events (abdominal cramps, vomiting and diarrhea) were limited to one individual receiving VSL#3. Results are limited by the small number of studies, unclear risk of bias and the small number of different types of probiotics used.
Grade of Evidence C 
 
Remarks
Acute pouchitis typically refers to symptoms (e.g. diarrhea, cramping, fecal urgency or incontinence) lasting <4 weeks; whereas in chronic pouchitis symptoms typically are present for >4 weeks. The primary outcome in the included studies was clinical improvement or remission in adults with acute or chronic pouchitis.

VSL#3® is a commercially available oral probiotic formulation containing eight different strains of bacteria (L. acidophilus, L. delbrueckii ssp. bulgaricus, L. plantarum, L.casei, B. infantis, B. longum, B. breve and S. salvarius ssp. thermophilus).

Additional Remarks

Active pouchitis (acute or chronic) can include symptoms including: diarrhea, increased stool frequency, abdominal cramping, fecal urgency, tenesmus (i.e. feeling the need to constantly pass stool) and incontinence.
 
4. Safety/Cautions with Probiotics
Recommendation
High Risk Groups
Probiotic products are generally safe for those in good general health. However, caution should be exercised when considering using probiotics among high risk groups such as critically ill patients and hospitalized and postoperative patients of all ages due to the risk of serious infection (bacteremia, fungemia, sepsis and endocarditis, in particular) among these vulnerable groups.

Indwelling Venous Catheter
Caution may also need to be taken if one has or is living with someone who has an indwelling venous catheter as there have been some cases of infection linked to environmental exposure (probiotic powder airborne contaminating catheter tips and then entering the blood stream this way).

Review Product Labels
Cautions/contraindications/risk information found on product label should be followed. Product labels generally caution against product use by those with an immune-compromising condition or those on long-term corticosteroid treatment.

Allergy
Those with known food allergies, particularly to cow’s milk, egg and soy proteins:

  • should avoid probiotics that indicate on the label that they could contain allergens
  • may even wish to avoid probiotics where the label explicitly indicates or suggests it is free of particular allergens as there have been some rare cases of anaphylactic reactions attributed to probiotics that contained allergens that the label had not declared. If not avoiding, then it would be prudent to at least consider the risk benefit ratio of using probiotics on the individual basis among those with allergies.

 

Evidence Summary

A systematic review and meta-analysis of hundreds of RCTs and clinical controlled trials on tens of thousands of children and adults being treated with probiotics found no difference in the rate of side-effects or adverse events between probiotic and control conditions. However, a few dozen case reports have found various probiotics to be strongly linked (and often culture confirmed) to infection such as sepsis, endocarditis, bacteremia (Lactobacillus, Bifidobacterium) and fungemia (Saccharomyces boulardii) among high risk and vulnerable population groups such as those who are critically ill, postoperative, hospitalized or who have venous indwelling catheters. Catheters were attributed as a route of transmission of infection even among individuals who were not administered probiotics themselves but were in a hospital bed beside individuals who were. The powder can become airborne and contaminate equipment, surfaces, hands etc. 

Case reports from Europe described a few cases of young children with cow’s milk allergy or both cow’s milk and egg allergy developing an anaphylactic reaction within moments of ingesting probiotic supplement. Additionally, experimental skin prick test trials motivated by these cases also found children with allergy to test positive to probiotic supplements that did not indicate on the label they contained allergens (cow’s milk proteins, hydyrolyzed soy proteins, egg protein). The culture medium which grows the probiotic can be a source of protein allergen in the resulting product.  
Grade of Evidence C
 
Remarks
Many probiotic product labels often note under caution or risk information that they should not be used by those with an immune-compromised condition or those on long-term corticosteroid treatment. Product labels also often encourage consulting a health care practitioner prior to use if pregnant, breastfeeding, taking other medications or supplements, have a health condition and to discontinue use if digestive upset occurs.