Commensal bacteria and essential amino acids control food choice behavior and reproduction
(A) Diagram depicting the strategy used to reconstitute the commensal population in the fly. (B) Yeast preference of animals kept on holidic diet with or without histidine (His). One group was not pretreated with the five commensals (untreated), the other was pretreated with the commensals (five bacteria), and the third was pretreated with inactivated commensals (inactivated five bacteria). (C) Yeast preference of animals kept on holidic diet, holidic diet without essential amino acids (eAAs), or holidic diet without eAAs pretreated with the commensal mix. (D) Yeast preference of animals kept on holidic diet with or without His and pretreated with varying concentrations of the commensal mix. (E) Yeast preference of Henna knockdown animals (tubulin > HennaIR1) kept on holidic diet lacking nonessential amino acids (neAAs), with or without pretreatment with the commensal mix, and holidic diet lacking neAAs with 2x tyrosine (Tyr) added back. (F) Number of eggs laid per female in 24 h of animals kept on holidic diet, holidic diet with all amino acids except His, isoleucine (Ile), or valine (Val), and with or without pretreatment with commensals. Black filled circles represent complete holidic medium or pretreatment with the bacteria mix. Open black circles represent flies that were not pretreated with bacteria mix. Amino acid (AA) deprivation is indicated as –His, –Ile or –Val. Data are pooled from two different rounds of experiments performed independently on different days. n = 39–40. (B, C, and E) Circles represent yeast preference in single assays, with a line representing the median and whiskers representing the interquartile range. Filled circles represent assays in which flies had been pretreated with commensals. n = 20–30. (D) Points represent median yeast preference and error bars represent the interquartile range. n = 15. (F) Circles represent eggs laid in single assays, with the line representing the mean. (B–E) Significance was tested using the Kruskal–Wallis test followed by Dunn’s multiple comparison test and in (F) using the one-way analysis of variance test followed by Bonferroni’s multiple comparison test (B–F) Not significant (ns) p > 0.05, * p < 0.05, ** p < 0.01, *** p < 0.001. Underlying data used in this Fig are provided in S1 Data.