The medical community has much to learn about probiotics and their effects on individual patients before the supplements can be broadly prescribed to achieve uniform effects, results of two new studies show. The randomized, controlled studies, which relied on serial biopsies rather than stool samples, show that whereas some patients appear to benefit of probiotics, others may have little response or potentially adverse reactions to the supplements.
And although it may be tempting to conclude that probiotics have no beneficial effect or are harmful, in reality, the results are more nuanced. But at the very least, the new data show that probiotics have the potential for detriment, which is an important discovery given that few studies look for, much less report, potential harms from probiotics.
Summed briefly, the studies, which relied on a mix of randomized studies in healthy human participants and animal data, found the following:
- Stool samples alone do not provide an accurate or sufficient portrait of the interactions between probiotics and a human host’s pre-existing microbiome and overall health.
- Some people’s microbiota resists colonization with probiotics, but others’ microbiomes change in response to probiotics, and sometimes in different ways at different points along the gastrointestinal tract.
- Probiotics administration after antibiotics can impede the microbiome’s return to baseline flora in humans, though the clinical significance of that is unclear.
- Characteristics of both an individual person and of their microbiome can largely predict probiotics’ effects in that person.
- The mouse model is not very informative or reliable in understanding probiotics’ effects in humans.
The findings have opened a Pandora’s box of questions that make manifest just how much there is to learn about probiotics. Physicians — and consumers — who want to explore therapeutic use of probiotics will need to accept the current uncertainties of their use, the highly personalized effects they have on different individuals, and the need to thoroughly comb through the evidence before making a decision on which probiotic to use, in whom, for what, and why.
“In our view, in the clinical decision-making process, probiotics should be regarded by physicians as any other medical treatment,” said Eran Elinav, MD, PhD, chair of immunology at the Weizmann Institute of Science in Rehovot, Israel, and senior author on both articles.
“In doing so, and in the unfortunate absence of any regulatory agency approval of probiotics for any indications, physicians should weigh the current evidence for clinical efficacy — debated and conflicting in many cases — and the potentially alarming long-term dysbiosis demonstrated upon probiotics usage with antibiotics, with its potential long-term implications, in making a case-by-case decision,” Elinav told Medscape Medical News.
“On a broader scale, the field is yearning for nonindustry-funded, high-quality multicenter trials to assess efficacy and adverse effects associated with probiotics use in affirming or debunking their utility. Until then, we believe that the burden of proof lies at the hands of those administering probiotics,” Elinav continued.
Reproduced by: Medscape
Date : October 15, 2018
