title: Effects of Lactobacillus acidophilus on gut microflora metabolic biomarkers in fed and fasted rats.
abstract: OBJECTIVE
  Little is known about fasting effects on gut bacterial metabolism. As probiotics are purported to be beneficial for health, this study aimed to investigate the response of gut microbial metabolism on fasting with or without probiotic administration.
  
  
  METHODS
  Sixty male adult Wistar rats were allocated to six experimental treatments, for 6 days, arranged under three nutritional schemes namely: (a) ad libitum feeding (control), (b) fasting for 3 days and re-feeding for the remainder (re-fed) and (c) fasting for 6 days combined with parenteral liquid treatment during the last 3 days (starved). Each nutritional scheme had one non-probiotic and one probiotic treatment receiving orally Lactobacillus acidophilus. Rat caecal digesta were analyzed for bacterial enzyme activities and volatile fatty acids (VFA).
  
  
  RESULTS
  Fasted rats had significantly lower activities of alpha-galactosidase, alpha-glucosidase and beta-glucosidase and higher activities of beta-galactosidase and azoreductase compared to control and re-fed rats, irrespective of probiotic administration. Results were variable regarding cholylglycine hydrolase (CGH), while there were no differences between treatments regarding beta-glucuronidase and arylsulfatase activity. Fasted rats had significantly lower caecal VFA concentration and different fermentation patterns. L. acidophilus resulted in significantly reduced azoreductase activity and increased caecal acetate levels in fasted rats. Re-feeding appeared to restore most enzyme activities, fermentation intensity and to some extent fermentation patterns at control treatment levels. L. acidophilus resulted in significantly reduced CGH activity and increased butyrate levels in re-fed rats.
  
  
  CONCLUSIONS
  The results indicate a health beneficial potential of L. acidophilus in fasted and re-fed nutritional states via reduction of harmful azoreductase and CGH activities and promotion of useful VFA components for colonic function and health.
authors.affiliation: Department of Nutritional Physiology and Feeding, Faculty of Animal Science and Aquaculture, Agricultural University of Athens, Iera Odos 75, Athens, Greece. kmountzouris@aua.gr
authors.forename: Konstantinos C
authors.initials: KC
authors.lastname: Mountzouris
authors.forename: Katerina
authors.initials: K
authors.lastname: Kotzampassi
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Tsirtsikos
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kapoutzis
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Fegeros
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002432:Cecum / Q000378:metabolism* / Q000382:microbiology*; D003106:Colon / Q000378:metabolism / Q000382:microbiology; D005215:Fasting / Q000378:metabolism*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation; D007779:Lactobacillus acidophilus / Q000254:growth & development / Q000502:physiology; D008297:Male; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D009601:Nitroreductases; D019936:Probiotics / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D000519:alpha-Galactosidase / Q000378:metabolism; D000520:alpha-Glucosidases / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D015415:Biomarkers; D005232:Fatty Acids, Volatile; D009247:NADH, NADPH Oxidoreductases; D009601:Nitroreductases; C021106:azoreductase; D000520:alpha-Glucosidases; D001617:beta-Glucosidase; D000519:alpha-Galactosidase; D001616:beta-Galactosidase; D000581:Amidohydrolases; C023154:choloylglycine hydrolase