Differences of Gut Microbial Diversity among Drug Users, Drug Abstainers and Methadone Maintenance Treatment Patients

This study aims to explore the gut microbial diversity of drug abstainers, drug users and methadone maintenance treatment (MMT) patients. Methods: 99 participants (28 drug abstainers, 16 MMT patients, 27 drug users and 28 healthy controls) with strict screening standards were enrolled. Dietary nutrition intake and fecal DNA of samples were obtained and microbial diversity was analyzed through high-throughput sequencing with bioinformatics tools and SPSS 20.0. Results: The abundance of Bifidobacterium and Lactobacillus in MMT patients was the highest (P = 0.001–0.025), which was positively correlated with Milk intake (r = 0.318–0.419, P < 0.01). Drug users showed the highest ratio of Ruminococcus (P = 0.001–0.042). Beta diversity analysis revealed the Jaccard distance of gut microbial community in drug abstainers was apart from that in healthy controls, while MMT patients clustered together with drug users. The dietary structures showed clustered distribution of drug users and drug abstainers, MMT patients was apart from others. Total energy of MMT patients was the highest (P < 0.05). Conclusion: Drug addiction and withdrawal could significantly shift human gut microbiota in Beta diversity and predominant taxa. Drug usage and diet both contribute more strongly to microbial divergence.