title: Effects of heat-killed Lactobacillus kunkeei YB38 on human intestinal environment and bowel movement: a pilot study.
abstract: It is well known that lactic acid bacteria supplementation is beneficial for intestinal conditions such as microbiota; however, the effects of killed-lactic acid bacteria on intestinal conditions are largely unclear. This study aimed to evaluate the effect of heat-killed Lactobacillus kunkeei YB38 (YB38) at a dose of approximately 10 mg/day on human intestinal environment and bowel movement. This single-blind study enrolled 29 female subjects with a low defecation frequency who consumed heat-killed YB38 at four increasing dosage levels: 0 (placebo), 2, 10, and 50 mg. Each dose was consumed daily for two weeks, with a two-week baseline period preceding the dosing-period and a two-week washout period ending the study. Observed levels of Bacteroides fragilis group significantly decreased with intake of heat-killed YB38 at ≥10 mg/day compared with levels during placebo intake (P<0.01). Faecal pH significantly decreased with 10 and 50 mg/day intake (P<0.01 and 0.05, respectively). Acetic acid levels tended to increase in faeces at the 50 mg/day dose (P<0.1). Bowel movement tended to increase in all heat-killed YB38 intake periods (P<0.1). In conclusion, heat-killed YB38 altered human intestinal microbiota at doses of ≥10 mg/day and tended to increase bowel movement at ≥2 mg/day. This is the first study to show the intestinal microbiota-altering effect of L. kunkeei and to report the bowel movement-improving effect of heat-killed lactic acid bacteria.
authors.affiliation: 1 Institute for Bee Products and Health Science, Yamada Bee Company, Inc. 194 Ichiba, Kagamino-cho, Tomata-gun, Okayama 708-0393, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Asama
authors.affiliation: 1 Institute for Bee Products and Health Science, Yamada Bee Company, Inc. 194 Ichiba, Kagamino-cho, Tomata-gun, Okayama 708-0393, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kimura
authors.affiliation: 1 Institute for Bee Products and Health Science, Yamada Bee Company, Inc. 194 Ichiba, Kagamino-cho, Tomata-gun, Okayama 708-0393, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kono
authors.affiliation: 1 Institute for Bee Products and Health Science, Yamada Bee Company, Inc. 194 Ichiba, Kagamino-cho, Tomata-gun, Okayama 708-0393, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tatefuji
authors.affiliation: 1 Institute for Bee Products and Health Science, Yamada Bee Company, Inc. 194 Ichiba, Kagamino-cho, Tomata-gun, Okayama 708-0393, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hashimoto
authors.affiliation: 2 Benno Laboratory, Innovation Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Benno
mesh_terms: D019342:Acetic Acid / Q000032:analysis; D000328:Adult; D058491:Bacterial Load; D001441:Bacteroides fragilis / Q000302:isolation & purification; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000187:drug effects*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007422:Intestines / Q000382:microbiology* / Q000502:physiology*; D007778:Lactobacillus; D008875:Middle Aged; D010865:Pilot Projects; D010919:Placebos / Q000008:administration & dosage; D019936:Probiotics / Q000008:administration & dosage*; D016037:Single-Blind Method
chemical_list: D010919:Placebos; D019342:Acetic Acid
keywords: Bacteroides fragilis group; Lactobacillus kunkeei; bowel movement; heat-killed; intestinal microbiota