Probiotics under fire: Guidelines slam lack of evidence for GI diseases

10 Jun 2020 --- There is not enough evidence to validate the use of probiotics for most digestive diseases, according to new guidelines from the American Gastroenterological Association (AGA). As a result of identifying just three clinical scenarios where probiotics may benefit patients, AGA only supports the use of certain probiotic formulations in specific settings. This could present a major blow to the burgeoning probiotic market, which has seen increasing attention in recent years.

“Patients taking probiotics for Crohn’s, ulcerative colitis or Irritable Bowel Syndrome (IBS) should consider stopping. The supplements can be costly and there isn’t enough evidence to prove a benefit or confirm lack of harm,” says Grace Lu of the University of Michigan, Ann Arbor, and guideline panel chair.

Mónica Olivares Martin, R&D Director at Biosearch Life (BSL) weighs in, telling NutritionInsight about the importance of clinical validation. “The concept of probiotics should not be generalized and each strain must clinically demonstrate if it is beneficial for a given health condition. We agree that there are products on the market whose efficacy has not been proven. However, recommendations should be directed at strains that have demonstrated a benefit for the consumer and not toward a general probiotic concept,” she explains. 

She continues that no risks associated with the consumption of probiotics have been described. “Even in premature, very fragile and susceptible babies, the administration of probiotics has shown beneficial effects. The benefits at the intestinal level are very varied, including preventing or treating diarrhea, improving symptoms related to inflammatory bowel conditions, necrotizing enterocolitis and infantile colic. Given the low risk of consumption, consumers should have the opportunity to know that there are products on the market that can help improve their health.”

AGA’s key guideline recommendations include: 

• For preterm, low birth-weight infants, specific probiotics can prevent mortality and necrotizing enterocolitis, reduce the number of days required to reach full feeds and decrease the duration of hospitalization.
• Certain probiotics should be considered for the prevention of C. difficile infection in adults and children who take antibiotics and for the management of pouchitis, a complication of ulcerative colitis that has been treated surgically.
• Probiotics do not appear to be beneficial for children in North America who have acute gastroenteritis. Therefore, they should not be given routinely to children who present to the emergency room due to diarrhea.
• There was insufficient evidence for AGA to make recommendations regarding the use of probiotics to treat C. difficile infection, Crohn’s disease, ulcerative colitis or IBS. 
• Well-designed clinical trials will be needed to refine these AGA recommendations on probiotics and to investigate other clinical conditions relevant to gastroenterology.
• Gastroenterologists should suggest the use of probiotics to their patients only if there is clear benefit. They should also recognize that the effects of probiotics are not species-specific, but strain- and combination-specific.

Providing objective guidance
The concept of probiotics should not be generalized and each strain must clinically demonstrate if it is beneficial for a given health condition, says BSL expert. According to AGA, this is the first clinical guidance to focus on probiotics across multiple gastrointestinal (GI) diseases, while also considering the effect of each single-strain or multi-strain formulation of probiotics independently. This is instead of grouping them all under the single umbrella of “probiotics.”

AGA also details that given the widespread use and often “biased” sources of information, it is essential that the public have objective guidance about the appropriate use of and indications for probiotics. AGA employed the gold standard for guideline development, GRADE methodology, to evaluate the available evidence on clinical efficacy of probiotics.

“While our guideline does highlight a few use cases for probiotics, more importantly, it underscores that the public’s assumptions about the benefits of probiotics are not well-founded. Additionally, there is also a major variation in results based on the formulation of the probiotic product,” adds Lu. 

Probiotic supplements come to the fore
Innova Market Insights reports that probiotic supplements are on the rise. While probiotics only represented 3 percent of supplement launches in 2015 and 2016, this rose to 10 percent in 2018. Meanwhile, capsules are the leading delivery format, accounting for 31 percent of probiotic supplement launches in 2017. However, powder is growing fast, leaping from 15 percent in 2014 and 22 percent in 2018. In 2019, 94 percent of launches included a digestive/liver health claim, while 49 percent were touted for immune health, according to the market researcher. 

In April, BLS announced a clinical trial to examine the effect of its Hereditum Immunactiv K8 product on COVID-19. Additionally, Lallemand partnered with Canadian companies Biotechnologies Ulysse and Bio-K Plus to develop a vaccine containing live bacteria against COVID-19.

Finally, the Digestive Disease Week event in May put the spotlight on a range of studies involving probiotics. It was revealed that over a quarter of gastroenterology patients use probiotics. This may be reflected in DuPont’s financial results, which revealed that its probiotic section is seeing its strongest growth to date. 

By Katherine Durrell