Background/Objectives: Unexplained infertility is a worldwide problem affecting a significant proportion of couples of reproductive age. Recent studies suggest that alterations in the vaginal microbiota are related to female infertility, while supplementation with some probiotic strains has been shown to improve pregnancy rates in couples experiencing this problem. This study aimed to evaluate the impact of oral administration of Ligilactobacillus salivarius CECT5713 on pregnancy success rates in couples with unexplained infertility prior to in vitro fertilization (IVF). Methods: Seventy couples were randomized to receive either a placebo or a probiotic intervention (one capsule per day containing an excipient only or 3 × 10⁹ viable cells of L. salivarius CECT5713 plus an excipient, respectively); 57 couples completed the study. Baseline data on demographics, health status (including gynecological and reproductive history), and lifestyle habits were collected. Vaginal swabs and semen samples were obtained from each couple before the intervention and immediately prior to IVF or upon confirmed pregnancy and were analyzed for microbiological (using both culture-dependent and -independent methods) and immunological profiles. Results: Oral administration of L. salivarius CECT5713 in couples with unexplained infertility scheduled for IVF resulted in a significantly higher pregnancy success rate (48.1%) compared to the placebo group (20.0%) (one-tailed Chi-square test; p < 0.024). The probiotic intervention improved both vaginal and semen immunological profiles, with no substantial changes observed in their microbial composition. Conclusions: These preliminary findings support the potential of L. salivarius CECT5713 supplementation to enhance fertility outcomes in couples with unexplained infertility.

Breastfeeding is the best way to feed an infant, although it can also be a source of abiotic contaminants such as heavy metals or bisphenol A (BPA). The early life exposure to these compounds can lead to serious toxic effects in both the short and long-term. These substances can reach breast milk through the mother’s habits, diet being one of the main routes of exposure. The aim of the present work was to analyse possible associations between the dietary habits of women and the content of major trace elements, BPA, fatty acids and lipids, and the microbiological and immunological profiles of human milk. Possible associations between major trace elements and BPA and the lipid, microbiological and immunological profiles were also analysed. The results of this study support that the microbiological composition of human milk is associated with the dietary habits of the women, and that the consumption of canned drinks is related to the presence of BPA in human milk. Furthermore, some relationships were found between the amount of major trace elements and the microbiological and immunological profile of the milk samples. Finally, the presence of BPA was associated with changes in the immunological profile of human milk.

HIV infection is considered a scenario of accelerated aging. Previous studies have suggested a link between aging, frailty, and gut dysbiosis, but there is a knowledge gap regarding the HIV population. Our objective was to compare the fecal bacteriome of older people with HIV (PWH) and non-HIV controls, and to assess potential links between gut dysbiosis and frailty. A total of 36 fecal samples (24 from PWH and 12 from non-HIV controls) were submitted to a metataxonomic analysis targeting the V3–V4 hypervariable region of the 16S rRNA gene. High-quality reads were assembled and classified into operational taxonomic units. Alpha diversity, assessed using the Shannon index, was higher in the control group than in the HIV group (p < 0.05). The relative abundance of the genus Blautia was higher in the HIV group (p < 0.001). The presence of Blautia was also higher in PWH with depression (p = 0.004), whereas the opposite was observed for the genus Bifidobacterium (p = 0.004). Our study shows shifts in the composition of the PWH bacteriome when compared to that of healthy controls. To our knowledge, this is the first study suggesting a potential link between depression and gut dysbiosis in the HIV population.