title: Modulation of fecal Clostridiales bacteria and butyrate by probiotic intervention with Lactobacillus paracasei DG varies among healthy adults.
abstract: BACKGROUND
  The modulation of gut microbiota is considered to be the first target to establish probiotic efficacy in a healthy population.
  
  
  OBJECTIVE
  This study was conducted to determine the impact of a probiotic on the intestinal microbial ecology of healthy volunteers.
  
  
  METHODS
  High-throughput 16S ribosomal RNA gene sequencing was used to characterize the fecal microbiota in healthy adults (23-55 y old) of both sexes, before and after 4 wk of daily consumption of a capsule containing at least 24 billion viable Lactobacillus paracasei DG cells, according to a randomized, double-blind, crossover placebo-controlled design.
  
  
  RESULTS
  Probiotic intake induced an increase in Proteobacteria (P = 0.006) and in the Clostridiales genus Coprococcus (P = 0.009), whereas the Clostridiales genus Blautia (P = 0.036) was decreased; a trend of reduction was also observed for Anaerostipes (P = 0.05) and Clostridium (P = 0.06). We also found that the probiotic effect depended on the initial butyrate concentration. In fact, participants with butyrate >100 mmol/kg of wet feces had a mean butyrate reduction of 49 ± 21% and a concomitant decrease in the sum of 6 Clostridiales genera, namely Faecalibacterium, Blautia, Anaerostipes, Pseudobutyrivibrio, Clostridium, and Butyrivibrio (P = 0.021), after the probiotic intervention. In contrast, in participants with initial butyrate concentrations <25 mmol/kg of wet feces, the probiotic contributed to a 329 ± 255% (mean ± SD) increment in butyrate concomitantly with an ∼55% decrease in Ruminococcus (P = 0.016) and a 150% increase in an abundantly represented unclassified Bacteroidales genus (P = 0.05).
  
  
  CONCLUSIONS
  The intake of L. paracasei DG increased the Blautia:Coprococcus ratio, which, according to the literature, can potentially confer a health benefit on the host. The probiotic impact on the microbiota and on short-chain fatty acids, however, seems to strictly depend on the initial characteristics of the intestinal microbial ecosystem. In particular, fecal butyrate concentrations could represent an important biomarker for identifying subjects who may benefit from probiotic treatment. This trial was registered at www.controlled-trials.com/isrctn as ISRCTN56945491.
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy;
authors.forename: Chiara
authors.initials: C
authors.lastname: Ferrario
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy;
authors.forename: Valentina
authors.initials: V
authors.lastname: Taverniti
authors.affiliation: Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parma, Italy; and.
authors.forename: Christian
authors.initials: C
authors.lastname: Milani
authors.affiliation: Sofar S.p.A., Trezzano Rosa, Italy.
authors.forename: Walter
authors.initials: W
authors.lastname: Fiore
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy;
authors.forename: Monica
authors.initials: M
authors.lastname: Laureati
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy;
authors.forename: Ivano
authors.initials: I
authors.lastname: De Noni
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy;
authors.forename: Milda
authors.initials: M
authors.lastname: Stuknyte
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy;
authors.forename: Bessem
authors.initials: B
authors.lastname: Chouaia
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy;
authors.forename: Patrizia
authors.initials: P
authors.lastname: Riso
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy; simone.guglielmetti@unimi.it.
authors.forename: Simone
authors.initials: S
authors.lastname: Guglielmetti
mesh_terms: D000328:Adult; D020148:Butyric Acid / Q000737:chemistry* / Q000378:metabolism; D004311:Double-Blind Method; D005243:Feces / Q000737:chemistry* / Q000382:microbiology*; D005260:Female; D016937:Gram-Positive Endospore-Forming Rods / Q000145:classification / Q000302:isolation & purification*; D006801:Humans; D007778:Lactobacillus; D008297:Male; D008875:Middle Aged; D019936:Probiotics; D055815:Young Adult
chemical_list: D020148:Butyric Acid