Choi SI, Son JH, Kim N, Kim YS, Nam RH, Park JH, Song C, Yu JE, Lee DH, Yoon K, Min H, Kim Y, Seok Y.  Changes in Cecal Microbiota and Short-chain Fatty Acid During Lifespan of the Rat.  J Neurogastroenterol Motil 2021;27:134-146.  https://doi.org/10.5056/jnm20148