Alterations in the Gut Microbiome Composition of People Living with HIV in the Asia-Pacific Region: A Systematic Review.

Human immunodeficiency virus (HIV) infection continues to present a global health issue. Recent studies have explored the potential role of the gut microbiome in HIV infection for novel therapeutic approaches. We investigated the gut microbiome composition of people living with HIV (PLHIV) in the Asia-Pacific region. This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. An electronic search was conducted in the PubMed/MEDLINE, Scopus, and ScienceDirect databases using keywords such as "HIV", "PLHIV", "AIDS", "gut microbiome", "gut dysbiosis", and "metagenomics". Only peer-reviewed and full-text studies published in English were included. A total of 15 studies from the Asia-Pacific region were included for analysis. Compared to healthy controls, PLHIV showed an increased abundance of Proteobacteria and its genera, which may be considered pathobionts, and decreased abundances of Bacteroidetes and several genera under Firmicutes with known short-chain fatty acid and immunoregulatory activities. Predominant taxa such as Ruminococcaceae and Prevotellaceae were also associated with clinical factors such as CD4 count, the CD4/CD8 ratio, and inflammatory cytokines. This review highlights gut microbiome changes among PLHIV in the Asia-Pacific region, indicating potential bacterial signatures for prognostication. The partial restoration of the microbiome toward beneficial taxa may ensure the long-term success of treatment, promoting immune recovery while maintaining viral load suppression.

Immunomodulatory potential of four candidate probiotic Lactobacillus strains from plant and animal origin using comparative genomic analysis.

Probiotic strains from different origins have shown promise in recent decades for their health benefits, for example in promoting and regulating the immune system. The immunomodulatory potential of four Lactobacillus strains from animal and plant origins was evaluated in this paper based on their genomic information. Comparative genomic analysis was performed through genome alignment, average nucleotide identity (ANI) analysis and gene mining for putative immunomodulatory genes. The genomes of the four Lactobacillus strains show relative similarities in multiple regions, as observed in the genome alignment. However, ANI analysis showed that L. mucosae LM1 and L. fermentum SK152 are the most similar when considering their nucleotide sequences alone. Gene mining of putative immunomodulatory genes studied from L. plantarum WCFS1 yielded multiple results in the four potential probiotic strains, with L. plantarum SK151 showing the largest number of genes at around 74 hits, followed by L. johnsonii PF01 at 41 genes when adjusted for matches with at least 30 % identity. Looking at the immunomodulatory genes in each strain, L. plantarum SK151 and L. johnsonii PF01 may have wider activity, covering both immune activation and immune suppression, as compared to L. mucosae LM1 and L. fermentum SK152, which could be more effective in activating immune cells and the pro-inflammatory cascade rather than suppressing it. The similarities and differences between the four Lactobacillus species showed that there is no definitive trend based on the origin of isolation alone. Moreover, higher percentage identities between genomes do not directly correlate with higher similarities in potential activity, such as in immunomodulation. The immunomodulatory function of each of the four Lactobacillus strains should be observed and verified experimentally in the future, since some the activity of some genes may be strain-specific, which would not be identified through comparative genomics alone.