Gut microbiome may influence tumor growth and cancer treatment efficacy, so it is a potential target for tumor prevention/treatment. This pilot study investigated the preventive and therapeutic effects of a probiotic strain, Lacticaseibacillus rhamnosus Probio-M9 (Probio-M9), against murine mammary cancer. Thirty-six female mice were randomly divided into three groups (n = 12 per group): control (without tumor transplantation), model (tumor transplantation; no probiotic administration), and probiotic (30-day oral gavage of probiotic, started seven days before tumor transplantation). Changes in tumor size were recorded, and blood, tumor tissue, and stool samples were collected at the end of the trial for analyses. Comparing with the model group, the probiotic group had a significantly smaller tumor volume (p < 0.05), a higher fecal microbiota Shannon diversity index, with significant modifications in the gut microbiota structure (p < 0.05), characterized by more Alistipes sp._2, Porphyromonadaceae bacterium_7, and Bacteroidales bacterium 55_9 (p < 0.05). Additionally, Probio-M9 administration elevated the serum IFN-γ, IL-9, IL-13, and IL-27 levels and several metabolites (e.g., pyridoxal, nicotinic acid, 3-hydroxybutyric acid, glutamine; p < 0.05), while reducing IL-5 (p < 0.05). These changes might be associated with the protective effect of Probio-M9 against mammary tumor growth. Thus, probiotic administration could harness host gut microbiome in anti-cancer responses.

In our previous study, a new fermented food (PWF) created by utilizing pineapple by-products and whey proteins as a matrix via co-fermentation with lactic acid bacteria and yeast was developed, and, in the current study, we examined the impact of a pineapple–whey protein fermentation product on a cefixime-induced dysbiosis model in mice using 16S sequencing and untargeted metabolomics techniques. The results indicated that the pineapple–whey protein fermentation product played a positive role in restoring the intestinal flora. In this study, cefixime reduced the overall abundance of intestinal flora and decreased the relative abundance of probiotics in the gut, while also inhibiting amino acid metabolism. The addition of PWF normalized the intestinal flora to a steady state, significantly increasing the populations of Weissella, Lactococcus, Faecalibaculum, and Bacteroides acidophilus, while decreasing the numbers of Akkermansia and Escherichia-Shigella. Additionally, PWF modulated microbial metabolites, such as L-glutamate and L-threonine, and upregulated amino-acid-related metabolic pathways, including those involving glycine, serine, and threonine. In conclusion, PWF can alleviate intestinal flora dysbiosis and metabolic disturbances induced by antibiotic interventions. It is suggested that PWF could be a potential dietary strategy for patients with antibiotic-associated diarrhea.

The development of plant-based functional beverages is often limited by inherent matrix defects, particularly undesirable off-flavors, astringency, and colloidal instability. Water kefir (WK), a highly resilient multispecies symbiotic consortium, offers a robust biorefining platform to address these challenges. This review systematically elucidates the underlying micro-ecological logic and biochemical mechanisms of WK-mediated plant matrix remodeling. We first detail how spatial niche differentiation and cross-feeding networks among lactic acid bacteria, yeasts, and acetic acid bacteria drive ecological homeostasis. Next, we highlight core molecular events that elevate sensory quality: protein unfolding for off-flavor elimination, enzymatic depolymerization of phenolics to mitigate astringency, and exopolysaccharide synthesis for rheological and flavor diffusion control. Finally, to overcome industrial scale-up challenges, we outline a precision fermentation framework, integrating systems multi-omics, real-time biomimetic monitoring, and sensory topological modeling. Ultimately, this synthesis provides theoretical guidance for the reverse flavor engineering and targeted nutritional design of novel plant-based beverages.

Water kefir is a non-dairy fermented beverage whose flavor arises from complex interactions among lactic acid bacteria, yeasts, and their metabolites. The volatile and metabolic profiles of water kefir fermented with unrefined brown sugar alone, without fruit adjuncts, remain poorly characterized. Here, water kefir was fermented for 72 h in a simplified unrefined brown sugar-only medium, and volatile organic compounds (VOCs) and metabolites were analyzed using gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography time-of-flight mass spectrometry (GC-TOF-MS)-based untargeted metabolomics. Twenty-six VOC signals (corresponding to 25 unique compounds) were identified, dominated by esters (8), aldehydes (5), and alcohols (4). Two distinct fermentation phases were revealed: an early stage (0–48 h) of rapid ester accumulation associated with shifts in starch, sucrose, and amino acid metabolism, and a late stage (48–72 h) marked by declining ester levels and increased metabolite co-variation network density. Under the investigated conditions, these temporal dynamics suggest that 48 h represents a candidate time point associated with an ester-rich volatile profile, whereas extending fermentation to 72 h yields a more acidic, organic acid- and amino acid-remodeled matrix. Overall, this study provides a preliminary chemical reference for brown sugar water kefir fermentation, warranting future sensory evaluation and validation across diverse water kefir grains.