Milk kefir alters fecal microbiota impacting gut and brain health in mice

Potassium sodium hydrogen citrate intervention on gut microbiota and clinical features in uric acid stone patients

The high recurrence rate of renal uric acid stone (UAS) poses a significant challenge for urologists, and potassium sodium hydrogen citrate (PSHC) has been proven to be an effective oral dissolution drug. However, no studies have investigated the impact of PSHC on gut microbiota and its metabolites during stone dissolution therapy. We prospectively recruited 37 UAS patients and 40 healthy subjects, of which 12 patients completed a 3-month pharmacological intervention. Fasting vein blood was extracted and mid-stream urine was retained for biochemical testing. Fecal samples were collected for 16S ribosomal RNA (rRNA) gene sequencing and short chain fatty acids (SCFAs) content determination. UAS patients exhibited comorbidities such as obesity, hypertension, gout, and dyslipidemia. The richness and diversity of the gut microbiota were significantly decreased in UAS patients, Bacteroides and Fusobacterium were dominant genera while Subdoligranulum and Bifidobacterium were poorly enriched. After PSHC intervention, there was a significant reduction in stone size accompanied by decreased serum uric acid and increased urinary pH levels. The abundance of pathogenic bacterium Fusobacterium was significantly downregulated following the intervention, whereas there was an upregulation observed in SCFA-producing bacteria Lachnoclostridium and Parasutterella, leading to a significant elevation in butyric acid content. Functions related to fatty acid synthesis and amino acid metabolism within the microbiota showed upregulation following PSHC intervention. The correlation analysis revealed a positive association between stone pathogenic bacteria abundance and clinical factors for stone formation, while a negative correlation with SCFAs contents. Our preliminary study revealed that alterations in gut microbiota and metabolites were the crucial physiological adaptation to PSHC intervention. Targeted regulation of microbiota and SCFA holds promise for enhancing drug therapy efficacy and preventing stone recurrence. KEY POINTS: • Bacteroides and Fusobacterium were identified as dominant genera for UAS patients • After PSHC intervention, Fusobacterium decreased and butyric acid content increased • The microbiota increased capacity for fatty acid synthesis after PSHC intervention.

Cooperative action of non-digestible oligosaccharides improves lipid metabolism of high-fat diet-induced mice

Non-digestible oligosaccharides are known to exert health-promoting effects. However, the specific mechanisms by which they regulate host physiology remain unclear. Understanding these mechanisms will facilitate the development of non-digestible oligosaccharide compositions that can achieve synergistic effects. This study selected three representative non-digestible oligosaccharides, namely xylo-oligosaccharides (XOS), galacto-oligosaccharides (GOS), and isomalto-oligosaccharides (IMO), to investigate their effects as dietary interventions on mice fed a high-fat diet. The results demonstrated that XOS and IMO synergistically mitigated weight gain and ectopic lipid deposition. Further analysis revealed that XOS significantly altered the composition of the gut microbiota, while IMO significantly enhanced insulin sensitivity via the PI3K/Akt pathway. Moreover, the combination of XOS and IMO synergistically promoted the oxidation and breakdown of fatty acids and increased the abundance of acetate and propionate-producing bacteria, such as Lactobacillus. These findings suggest a novel strategy for obesity management based on dietary intervention with XOS and IMO.

Impact of Lyophilized Milk Kefir-Based Self-Nanoemulsifying System on Cognitive Enhancement via the Microbiota-Gut-Brain Axis

Chronic inflammatory bowel disorders (IBDs) are characterized by altered intestinal permeability, prompting inflammatory, oxidative stress, and immunological factors. Gut microbiota disorders impact brain function via the bidirectional gut-brain axis, influencing behavior through inflammatory cascades, oxidative stress, and neurotransmitter levels. This study highlights the potential effect of integrating lyophilized milk kefir alone and lyophilized milk kefir as solid carriers loaded with a self-nanoemulsifying self-nanosuspension (SNESNS) of licorice extract on an induced chronic IBD-like model in rats. Licorice-SNESNS was prepared by the homogenization of 30 mg of licorice extract in 1 g of the selected SNEDDS (30% Caraway oil, 60% Tween 20, and 10% propylene glycol (w/w)). Licorice-SNESNS was mixed with milk kefir and then freeze-dried. Dynamic TEM images and the bimodal particle size curve confirmed the formation of the biphasic nanosystems after dilution (nanoemulsion and nanosuspension). Daily oral administration of lyophilized milk kefir (100 mg/kg) loaded with SNESNS (10 mg/kg Caraway oil and 1 mg/kg licorice) restored normal body weight and intestinal mucosa while significantly reducing submucosal inflammatory cell infiltration in induced rats. Importantly, this treatment demonstrated superior efficacy compared to lyophilized milk kefir alone by leading to a more significant alleviation of neurotransmitter levels and improved memory functions, thereby addressing gut-brain axis disorders. Additionally, it normalized fecal microbiome constituents, inflammatory cytokine levels, and oxidative stress in examined tissues and serum. Moreover, daily administration of kefir-loaded SNESNS normalized the disease activity index, alleviated histopathological changes induced by IBD induction, and partially restored the normal gut microbiota. These alterations are associated with improved cognitive functions, attributed to the maintenance of normal neurotransmitter levels and the alleviation of triggered inflammatory factors and oxidative stress levels.

Effects of kefir consumption on gut microbiota and health outcomes in women with polycystic ovary syndrome

Polycystic Ovary Syndrome (PCOS), which is common among women of reproductive age, is characterized by low-grade chronic inflammation and is associated with several health problems and dysbiosis. Kefir has been shown to have many beneficial health effects; however, its effect on PCOS is unknown. This study aimed to examine the effect of kefir on the intestinal microbiota and health outcomes in PCOS. In this intervention study, 17 women with PCOS consumed 250 mL/day of kefir (containing Lactobacillus kefiranofaciens subsp. kefiranofaciens, Lactobacillus kefiranofaciens subsp. kefirgranum, Lactobacillus kefiri, Lactobacillus acidophilus, Lactobacillus parakefiri, Lactobacillus bulgaricus, Lactobacillus reuteri, Lactobacillus casei, Lactobacillus fermentum, Lactobacillus helveticus, Lactococcus lactis, Leuconostoc mesentereoides, Bifidobacterium bifidum, Streptococcus thermophilus, Kluyveromyces marxianus, Kluyveromyces lactis, Acetobacter pasteurianus, and Saccharomyces cerevisiae) for 8 weeks. Food consumption and physical activity records, anthropometrical measurements, quality of life, and fecal and blood samples were taken at the study's beginning and end. Quality of life in mental health (58.8 ± 15.08; 64.0 ± 15.23, respectively) and physical function (95.00 and 100.00, respectively) categories showed a significant increase after kefir intervention (p < .05). Additionally, Interleukin-6 (IL-6), one of the inflammatory cytokines, significantly decreased (174.00 and 109.10 ng/L, respectively) (p < .05). The intestinal barrier permeability was evaluated with zonulin, and no significant change was observed. Gut microbiota analysis showed that while the relative abundance of the class Bacilli and genus Lactococcus significantly increased, the genus Holdemania decreased with kefir consumption (p < .05). In conclusion, kefir appears to be beneficial for improving the microbiota and some health outcomes, like reducing inflammation and improving quality of life in PCOS. Therefore, kefir may be useful in the treatment of PCOS.

Postbiotics in the Bakery Products: Applications and Nutritional Values

In recent years, the consumption of postbiotics has gained significant attention due to their potential health benefits. However, their application in the bakery industry remains underutilized. This review focuses on recent advances in the use of postbiotics, specifically the metabolites of lactic acid bacteria, in bakery products. We provide a concise overview of the multifaceted benefits of postbiotics, including their role as natural antioxidants, antimicrobials, and preservatives, and their potential to enhance product quality, extend shelf-life, and contribute to consumer welfare. This review combines information from various sources to provide a comprehensive update on recent advances in the role of postbiotics in bakery products, subsequently discussing the concept of sourdough as a leavening agent and its role in improving the nutritional profile of bakery products. We highlighted the positive effects of postbiotics on bakery items, such as improved texture, flavor, and shelf life, as well as their potential to contribute to overall health through their antioxidant properties and their impact on gut health. Overall, this review emphasizes the promising potential of postbiotics to revolutionize the bakery industry and promote healthier and more sustainable food options. The integration of postbiotics into bakery products represents a promising frontier and offers innovative possibilities to increase product quality, reduce food waste, and improve consumer health. Further research into refining techniques to incorporate postbiotics into bakery products is essential for advancing the health benefits and eco-friendly nature of these vital food items.

Microbiome-based precision nutrition: Prebiotics, probiotics and postbiotics

Microorganisms have been used in nutrition and medicine for thousands of years worldwide, long before humanity knew of their existence. It is now known that the gut microbiota plays a key role in regulating inflammatory, metabolic, immune and neurobiological processes. This text discusses the importance of microbiota-based precision nutrition in gut permeability, as well as the main advances and current limitations of traditional probiotics, new-generation probiotics, psychobiotic probiotics with an effect on emotional health, probiotic foods, prebiotics, and postbiotics such as short-chain fatty acids, neurotransmitters and vitamins. The aim is to provide a theoretical context built on current scientific evidence for the practical application of microbiota-based precision nutrition in specific health fields and in improving health, quality of life and physiological performance.

The composition of Tibetan kefir grain TKG-Y and the antibacterial potential and milk fermentation ability of S. warneri KYS-164 screened from TKG-Y

This study utilized high-throughput sequencing and SEM observation to elucidate the microbial composition of a Tibetan herder's homemade kefir grain named TKG-Y. Subsequently, S. warneri KYS-164 was isolated from TKG-Y, which can produce mixed protein substances with antibacterial activity, namely bacteriocin-like inhibitory substances (BLIS). BLIS can significantly reduce the growth rate of Escherichia coli 366-a, Staphylococcus aureus CICC 10384 and mixed strains at low concentrations (1 × MIC). The presence of the warnericin-centered gene cluster in KYS-164 may explain the antibacterial properties of the BLIS. Pepsin and an acidic environment can reduce the number of colonies of KYS-164 by 2.5 Log10 CFU mL-1 within 1 h, and reduce the antibacterial activity of BLIS by 21.48%. S. warneri KYS-164 showed no antibiotic resistance and biological toxicity after 80 subcultures, while BLIS produced by 40 generations of the strain retained their inhibitory efficacy against pathogenic bacteria. After 48-hour fermentation of milk with KYS-164, volatile compounds such as aldehydes, phenols, esters, and alcohols, giving it a floral, fruity, milky, oily, and nutty aroma, were released, enriching the sensory characteristics of dairy products. This study not only revealed the bacterial colony composition information of home-made kefir grain TKG-Y but also discovered and proved that S. warneri KYS-164 has the potential to inhibit bacteria and ferment dairy products. This will provide a basis for subsequent applied research on KYS-164.

Bibliometric analysis of water kefir and milk kefir in probiotic foods from 2013 to 2022: A critical review of recent applications and prospects

Although milk kefir and water kefir have different physical, chemical and microbiological characteristics, several microbial species that make up kefir stand out with probiotic functions. Furthermore, because it is suitable for a variety of substrates, kefir and the species of probiotic microorganisms that make it up are seen as a promising alternative in the development of probiotic and health-promoting foods. The aim of this study was to carry out a bibliometric analysis of water kefir and milk kefir in probiotic foods and to critically analyze recent applications and prospects. Using the Scopus database, 202 documents published between 2013 and 2022 were identified and submitted to bibliometric analysis using the VOSviewer software. Regarding recent applications, 107 documents published between 2021 and June 2023 were identified. It was observed that, in the literature consulted, no study used bibliometric analysis to evaluate the use of water kefir and milk kefir in probiotic foods. Due to the presence of probiotic species, kefir has been listed as an alternative for the production of new probiotic food matrices that are beneficial to health. Recent applications show kefir's potential in the development of probiotic products based on fruit and fruit juice, whey beverages, fermented milks and derivatives, and alcoholic beverages such as beers.

Functional effects of yacon (Smallanthus sonchifolius) and kefir on systemic inflammation, antioxidant activity, and intestinal microbiome in rats with induced colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers with high morbidity and mortality. The modulation of intestinal health through the administration of pro- and prebiotics may be a viable alternative to reduce the risk of CRC. This study aimed to evaluate the functional effects of yacon and kefir, isolated or associated, in rats with colorectal cancer. Adult Wistar rats were divided into five groups (n = 8): HC (healthy control AIN-93M diet), CC (CCR + AIN-93M diet), Y (CCR + AIN-93 M + yacon diet), K (CCR + AIN-93-M + kefir diet) and YK (CCR + AIN-93 M + yacon + kefir diet). Colorectal carcinogenesis was induced in groups CC, Y, K, and YK with 1,2-dimethylhydrazine (55 mg kg-1, subcutaneously) for 5 weeks. From the 6th week onwards, the experimental groups were fed the respective diets. In the 15th week, urine was collected for analysis of intestinal permeability and then the animals were euthanized. Yacon increased acetate levels, reduced pH and carcinogenic neoplastic lesions, and increased the abundance of bacteria related to the fermentation of non-digestible carbohydrates, such as the genera Dorea, Collinsela, and Bifidobacteria. On the other hand, kefir increased macroscopic neoplastic lesions and increased the abundance of Firmicutes and Clostridium. The association of yacon + kefir increased the number of carcinogenic lesions, despite a reduction in pH and beneficial bacteria prevalence. Thus, it is concluded that yacon, unlikely kefir, is a promising alternative to mitigate the manifestations of induced carcinogenesis in rats.