The study published in the journal Microbiology Spectrum investigated the gluten-degrading activity of a probiotic blend of seven Lactobacillus and Bacillus strains supplied by German Manufacturer Evonik (marketed as ‘In Vivo Biotics Gluten Tolerance’).
The placebo-controlled trial involving 70 healthy volunteers, found that the probiotic enhanced gluten digestion compared to placebo when participants were fed increasing quantities of gluten over 42 days.
“Our study presents a novel probiotic preparation suitable for people suffering from gluten-related disorders during gluten-free diet (GFD) and for healthy individuals because it enhances gluten digestion and promotes gut microbiota functionality,” the authors from Italy concluded.
Gluten-free
Gluten is a major protein in Western diets, with up to 20 g gluten/day. However, gluten resists complete digestion - gluten peptides larger than 10 amino acids are resistant to digestion due to their high proline content, and humans lack the nine peptidases required to hydrolyze gluten peptides with proline fully. This can cause issues for some people who suffer from celiac disease (1% of the population) and other gluten-related disorders (up to 5%).
A gluten-free diet (GFD) is essential for managing celiac disease symptoms but is hard to maintain due to cross-contamination and other challenges. Gluten-free products often still contain trace amounts of gluten, and approximately only 45% of celiac patients adhere effectively to a GFD.
“Because gluten must be strictly avoided to stop autoimmune reactions and related health problems, celiac disease and gluten sensitivity present difficult hurdles,” the authors of the research noted.
“However, because of the hidden presence of gluten in many food products and the constant danger of cross-contamination during food preparation and processing, total avoidance is frequently challenging.”
The researchers previously screened bacterial strains for their gluten-degrading capabilities under simulated gastrointestinal conditions, and found that a preparation containing lactic acid bacteria, bacilli, bacterial cytoplasmic extracts, and bacterial proteases could assist in vitro gluten degradation.
Probiotic effect
The new study consisted of a 32-day probiotic or placebo administration period, followed by 10 days of wash-out.
After a preliminary GFD period to eliminate residual gluten from feces, increasing amounts of gluten in capsule form (50 mg–10 g) were administered, each one for four consecutive days.
Fecal samples were collected at baseline, 10 days of GFD, four days of 50 mg/day gluten intake, four days of 1 g/day gluten intake, four days of 3 g/day gluten intake, and 20 days of 10 g/day gluten intake, of which the last 10 days was the wash-out.
Results showed that, compared to placebo, the feces of volunteers fed with probiotics showed much lower amounts of residual gluten. The probiotics were also found to regulate the intestinal microbial communities, improving the diversity of genera essential for preserving homeostasis.
Quantitative PCR confirmed all probiotics persisted during the intervention, some also during wash-out, and the probiotics promoted a fecal metabolome with potential immunomodulating activity, mainly related to derivatives of branched-chain amino acids and short-chain fatty acids.
The authors suggested that the results were due to three potential mechanisms: the hydrolysis of gluten into small non-immunogenic polypeptides; limited access of immunogenic polypeptides to the lamina propria and reduced epithelial permeability; and maintenance of the gut microbiota homeostasis, with regulation of both internal and adaptive immune systems.
“Our present study is the only randomized, placebo-controlled trial applying a synergistic consortium of probiotic bacteria for gluten degradation, with positive repercussions for not only gluten-related disorders but also enhancing the overall digestion of this unusual protein in healthy individuals,” they stated.
The authors noted that the ‘untapped potential of gluten-degrading bacteria and their application in addressing the limitations of gluten-related disorder management’ emphasized the significance of the result, however noting that ‘validation is required in follow-up studies also involving participants with CD’.
Journal: Microbiology Spectrum
doi: https://doi.org/10.1128/spectrum.03524-23
“Novel probiotic preparation with in vivo gluten-degrading activity and potential modulatory effects on the gut microbiota”
Authors: Nikoloudaki, O. Et al.