title: Regulatory effect of paraprobiotic Lactobacillus gasseri CP2305 on gut environment and function.
abstract: BACKGROUND
  Lactobacillus gasseri CP2305 (CP2305) is a strain of Lactobacillus isolated from a stool sample from a healthy adult that showed beneficial effects on health as a paraprobiotic. In a previous study, we demonstrated that CP2305-fermented heat-treated milk modified gut functions more than artificially acidified sour milk. Thus, the regulatory activity of the former beverage was attributed to the inactivated CP2305 cells.
  
  
  OBJECTIVE
  The aim of this study was to elucidate the contribution of non-viable paraprobiotic CP2305 cells to regulating human gut functions. We thus conducted a randomized, placebo-controlled, double-blinded parallel group trial.
  
  
  METHODS
  The trial included 118 healthy participants with relatively low or high stool frequencies. The test beverage was prepared by adding 1×10(10) washed, heat-treated, and dried CP2305 cells directly to the placebo beverage. The participants ingested a bottle of the assigned beverage daily for 3 weeks and answered daily questionnaires about defecation and quality of life. Fecal samples were collected and the fecal characteristics, microbial metabolite contents of the feces and composition of fecal microbiota were evaluated.
  
  
  RESULTS
  The number of evacuations and the scores for fecal odors were significantly improved in the group that consumed the CP2305-containing beverage compared with those of the group that consumed the placebo (p=0.035 and p=0.040, respectively). Regarding the fecal contents of microbial metabolites, the level of fecal p-cresol was significantly decreased in the CP2305 group relative to that of the placebo group (p=0.013). The Bifidobacterium content of the intestinal microbiota was significantly increased in the CP2305 group relative to that of the placebo group (p<0.008), whereas the content of Clostridium cluster IV was significantly decreased (p<0.003). The parasympathetic nerve activity of the autonomic nervous system became dominant and the total power of autonomic activity was elevated in the CP2305 group (p=0.0401 and p=0.011, respectively).
  
  
  CONCLUSIONS
  The continuous ingestion of heat-treated CP2305 cells clearly affected intestinal functionality. This is the first report of sterilized Lactobacillus cells having a significant impact on the environment and functions of the intestinal tract. The observed effects might be due, at least in part, to the brain-gut interaction.
authors.affiliation: Research & Development Center, Asahi Group Holdings, Ltd., Sagamihara-shi, Kanagawa, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Sugawara
authors.affiliation: Research & Development Center, Asahi Group Holdings, Ltd., Sagamihara-shi, Kanagawa, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sawada
authors.affiliation: Research & Development Center, Asahi Group Holdings, Ltd., Sagamihara-shi, Kanagawa, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: Research & Development Center, Asahi Group Holdings, Ltd., Sagamihara-shi, Kanagawa, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Aihara
authors.affiliation: Research & Development Center, Asahi Group Holdings, Ltd., Sagamihara-shi, Kanagawa, Japan.
authors.forename: Yumeko
authors.initials: Y
authors.lastname: Aoki
authors.affiliation: PI-Food Service Division, Clinical Support Corporation, Sapporo, Hokkaido, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Takehara
authors.affiliation: Medical Corporation Hokubukai Utsukushigaoka Hospital, Sapporo, Hokkaido, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Takano
authors.affiliation: Research & Development Center, Asahi Group Holdings, Ltd., Sagamihara-shi, Kanagawa, Japan; shigeru.fujiwara@asahigroup-holdings.com.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Fujiwara
keywords: abdominal symptoms; bacterial flora; defecation habits; heat-inactivated lactic acid-producing bacilli; intraluminal environment; parasympathetic activation