Probiotics beyond digestion: New research frontiers

May 13, 2020

Immune health is on a lot of people’s minds these days. “The immune system is one of the most complex in the body, and also one of the most important, as its prime function is to protect us against all kinds of infections—including viral,” says Sid Shastri, MSc, director of product development and marketing, Kaneka Probiotics (Newark, CA).

And while the immune system comprises everything from the thymus, tonsils, adenoids, and spleen to lymph glands and bone marrow, “scientists estimate that between 50% and 75% of all immune cells reside in the gastrointestinal tract as gut-associated lymphoid tissue, or GALT,” Shastri says. “So, it’s no understatement to claim that a healthy immune system emanates from a healthy gut.”

A healthy gut emanates, in part, from a healthy probiotic supplementation routine. But probiotics’ benefits go well beyond the gut, as well. And what we’re seeing these days is a renewed appreciation—and deeper understanding—of the benefits of probiotics.


Growth Medium

While consumers are hardly pinning their hopes on a supplement-based cure for the current COVID-19 pandemic—and no responsible party would suggest they do so—the pandemic reminds us that baseline health is tantamount to an insurance policy at times like this, and that what we take into our bodies can bolster and defend it against illness.

“As such, probiotic intake is becoming more prevalent,” says John Deaton, vice president of science and technology, Deerland Probiotics & Enzymes (Kennesaw, GA). “We’re seeing probiotics not only in supplements but increasingly in a variety of functional foods and beverages, from kombucha and hot chocolate to breakfast cereals and sports bars.”

The numbers back him up. Nutrition Business Journal reports “sizable 7% sales jumps in 2017 and 2018” for probiotic products, Deaton notes, and though growth evened out at a steady 2% in 2019, the calmer pace, Deaton surmises, is “likely because probiotics evolved from fad to must-have.”

Indeed, only 5% of supplement users included probiotics in their regimens in 2008, but that percentage had more than doubled to 13% by 2016, according to that year’s Council for Responsible Nutrition’s Consumer Survey on Dietary Supplements.


Mounting Evidence

It took probiotics to get to that point. While Elie Metchnikoff first observed the beneficial bacteria back in 1905, almost a century had passed before the International Scientific Association for Probiotics and Prebiotics arose in 2002, notes Shaheen Majeed, president worldwide, Sabinsa (East Windsor, NJ).

“Subsequent to that,” he continues, “the World Health Organization’s establishment of a probiotic definition then stimulated the rapid growth in research, clinical trials, and safety assessments we see now.”

And research really is mounting. “New discoveries are emerging at a fast pace,” Deerland’s Deaton says. His back-of-the-envelope PubMed search uncovered more than 27,000 papers published thus far, 13,017 of which dropped within the last five years and 3,770 of which arrived in 2019 alone. And with 1,091 papers going live in the first three months of 2020, he says, “That’s more than 12 papers per day!”


Firm Foundation

The research intensity reflects probiotics’ importance to “both human and animal health and wellbeing,” Deaton says. “And it’s incredibly important that this research be published through the process of rigorous peer review and made available for all, including research and data showing negative results.”

Category insiders agree. As Kaneka’s Shastri says, “Rigorous research isn’t just important for probiotics; it’s the essential foundation of the category.”

Jennifer Montgomery, regional probiotics marketing manager, DuPont Nutrition & Biosciences (Madison, WI), even believes that investment in clinical research is the industry standard, and a sign of a company’s seriousness.

“Probiotic research is increasingly being performed with rigor similar to what we see in medical research,” she adds. “Although probiotics’ aim is to support and maintain health, statements around this aim rightfully receive similar scrutiny as medical research. As a category, therefore, we must be confident that what we recommend is backed by sound data.”

Thankfully, much of it is. Bérengère Feuz, marketing director, Lallemand Health Solutions (Montreal), has noticed an encouraging maturation of clinical-study quality over the past 15 years, with protocols following best practices and researchers tapping into advanced technologies and multiple assessments, including microbiota analysis in stool samples, biomarker collection from saliva and blood, and the use of validated questionnaires to gauge symptom improvement objectively. “Clinical and mechanistic studies are essential to better understanding probiotics’ modes of action and benefits,” she says.

For his part, Sabinsa’s Majeed sees valid studies as having three core elements: “testing the health benefit in a randomized, controlled clinical trial in a heterogeneous population; the dose and viability of the probiotic used for study; and the genomic characterization of the probiotic strain.”


One Study Does Not Fit All

Matters of probiotic dose and strain repeatedly emerge as key to any study’s conclusions. As Shastri says, “Evidence points out again and again that probiotic properties and doses are strain-specific.” In other words, the efficacy and mechanisms of action attributable to one strain aren’t necessarily applicable to others.

“Moreover,” Shastri adds, “some studies show a plateau effect above a certain dose. Therefore, any health claims must be based on studies using the precise strains and doses being offered to consumers.”

Study results also depend on the subject populations involved, Deerland’s Deaton adds. “Although age populations in probiotic trials haven’t necessarily expanded,” he says, “it’s becoming clearer that a careful breakdown in age between children and adults is important in clarifying benefits.”

For example, a child’s microbiome has largely formed by age three; thus, many microbiome-related effects appear in cohorts younger than this, Deaton explains. By contrast, because the diversity of key microbiota species decreases with age, “supplementation with probiotics in this older cohort can yield specific immune benefits for this population.”

Adding to the specificity are studies that focus on probiotic effects in different gender and lifestyle cohorts, Deaton continues, “with distinct benefits seen among women and athletes.”

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