Heyndrickxia coagulans SANK70258 supplementation was also associated with an induction of anti-inflammatory effects via increased levels of butyrate (a short chain fatty acid) in the intestine.
“The results of this study showed that URTI-related scores, such as runny nose and sore throat scores, and the cumulative number of days of these symptoms during the intervention period were significantly lower in the HC [H. coagulans] group than in the placebo group, suggesting that HC may have a mitigating effect on URTI symptoms,” wrote scientists from Mitsubishi Chemical Corporation and Doujin Memorial Foundation Meiwa Hospital in Frontiers in Immunology.
Heyndrickxia coagulans was formerly known as Bacillus coagulans.
The study adds to an ever-growing body of science supporting the potential immune benefits of specific probiotic strains. Between 70 and 80% of the body's immune cells are located in the gut, and the intestinal microbiome is known to play a central role in immune system regulation.
Study details
The new randomized, double-blind, placebo-controlled, parallel-group study included 79 people with an average age of about 48 who were randomly assigned to receive daily H. coagulans supplements (1 billion CFUs per serving) or placebo for eight weeks.
The results showed that, based on questionnaires, the probiotic was associated with a significant reduction in symptoms of URTI, including runny nose, nasal congestion, sneezing, and sore throat scores. In addition, the cumulative number of days of these symptoms was also lower in the H. coagulans group, compared to placebo.
The Japan-based scientists also found that the probiotic group experienced significant increases in levels of salivary secretory immunoglobulin A (sIgA), the main immune factor in saliva and known to be the first line of defense in protecting against infection, compared to placebo. There was also a tendency for natural killer (NK) cell activity to be higher in the probiotic group, but the changes did not reach statistical significance between the groups.
The data also showed that H. coagulans ingestion was associated with significantly higher butyrate levels, compared with placebo. Additional in vitro tests using peripheral blood mononuclear cells (PBMCs) obtained from blood samples revealed significantly suppressed levels of PBMC-produced IL-6 and TNFalpha after the cells were exposures to an inactivated flu virus.
“[Butyrate] is recognized by GPR109A, a receptor on dendritic cells and macrophages, and is known to suppress excessive inflammation by inducing anti-inflammatory effects, such as Treg activation,” explained the researchers. “In addition, a meta-analysis of athletes suggested that one of the points of action of probiotics in alleviating URTI may be the suppression of IL-6 and TNFalpha.”
The researchers also found that blood cortisol levels were significantly reduced in the probiotic group after eight weeks of supplementation, compared to baseline. “Cortisol is widely used as a marker to assess stress; therefore, HC may also contribute to stress reduction,” they wrote.
Source: Frontiers in Immunology
2024, Volume 15, doi: 10.3389/fimmu.2024.1389920
“Heyndrickxia coagulans strain SANK70258 suppresses symptoms of upper respiratory tract infection via immune modulation: a randomized, double-blind, placebo-controlled, parallel-group, comparative study”
Authors: M. Aida, et al.