2022-08-01 イリノイ大学アーバナ・シャンペーン校
イリノイ大学の動物科学者の新しい研究は、変化が1週間未満で行われることを記録しています。
チームは、犬に一般的なドライキブル食を2週間与えた後、突然新しい食餌に切り替えて、さらに14日間与えました。半数の犬は高脂肪・高タンパクの缶詰を食べ、残りの半数は高繊維質のキブルを食べた。一方、研究者たちは、食事が変わってから2日後と、その後4日ごとにウンチを採取した。科学には再現性が求められるため、研究者らは、2回目の実験では、犬を逆の実験食に切り替えて、すべてを実施した。
研究チームは、それぞれの糞便サンプルから、犬の健康全般に影響を及ぼす可能性のある微生物の代謝産物を抽出した。また、糞便サンプルに含まれる細菌種を同定し、微生物群集が時間とともにどのように変化したかを明らかにしました。最後に、代謝産物と細菌種を関連付けました。
<関連情報>
- https://aces.illinois.edu/news/new-dog-food-study-shows-fidos-gut-bacteria-could-turn-over-within-week
- https://animalmicrobiome.biomedcentral.com/articles/10.1186/s42523-022-00194-9
健康な成犬における糞便中のマイクロバイオームと代謝産物の縦断的データから、食事の急激な変化とその後の安定化が示される Longitudinal fecal microbiome and metabolite data demonstrate rapid shifts and subsequent stabilization after an abrupt dietary change in healthy adult dogs
Ching-Yen Lin,Aashish R. Jha,Patrícia M. Oba,Sofia M. Yotis,Justin Shmalberg,Ryan W. Honaker & Kelly S. Swanson
Animal Microbiome Published:01 August 2022
DOI:https://doi.org/10.1186/s42523-022-00194-9
Abstract
Background
Diet has a large influence on gut microbiota diversity and function. Although previous studies have investigated the effect of dietary interventions on the gut microbiome, longitudinal changes in the gut microbiome, microbial functions, and metabolite profiles post dietary interventions have been underexplored. How long these outcomes require to reach a steady-state, how they relate to one another, and their impact on host physiological changes are largely unknown. To address these unknowns, we collected longitudinal fecal samples following an abrupt dietary change in healthy adult beagles (n = 12, age: 5.16 ± 0.87 year, BW: 13.37 ± 0.68 kg) using a crossover design. All dogs were fed a kibble diet (control) from d1-14, and then fed that same diet supplemented with fiber (HFD) or a protein-rich canned diet (CD) from d15-27. Fresh fecal samples were collected on d13, 16, 20, 24, and 27 for metabolite and microbiome assessment. Fecal microbial diversity and composition, metabolite profiles, and microbial functions dramatically diverged and stabilized within a few days (2 d for metabolites; 6 d for microbiota) after dietary interventions. Fecal acetate, propionate, and total short-chain fatty acids increased after change to HFD, while fecal isobutyrate, isovalerate, total branched-chain fatty acids, phenol, and indole increased after dogs consumed CD. Relative abundance of ~ 100 bacterial species mainly belonging to the Firmicutes, Proteobacteria, and Actinobacteria phyla increased in HFD. These shifts in gut microbiome diversity and composition were accompanied by functional changes. Transition to HFD led to increases in the relative abundance of KEGG orthology (KO) terms related to starch and sucrose metabolism, fatty acid biosynthesis, and amino sugar and nucleotide sugar metabolism, while transition to CD resulted in increased relative abundance of KO terms pertaining to inositol phosphate metabolism and sulfur metabolism. Significant associations among fecal microbial taxa, KO terms, and metabolites were observed, allowing for high-accuracy prediction of diet group by random forest analysis.
Conclusions
Longitudinal sampling and a multi-modal approach to characterizing the gastrointestinal environment allowed us to demonstrate how drastically and quickly dietary changes impact the fecal microbiome and metabolite profiles of dogs following an abrupt dietary change and identify key microbe-metabolite relationships that allowed for treatment prediction.
