Search

Alxa Bactrian camel meat is an organic diet that provides balanced nutrition and is easy to digest and absorb. Despite its potential, it is currently underutilized. To develop a new type of camel jerky, this study utilized a single-factor design method to optimize the formula and fermentation process parameters of Alxa Bactrian camel jerky. Additionally, the physical and chemical composition, nutritional components, protein degradation, and microbial changes of the camel jerky were analyzed to evaluate the nutritional benefits of the new camel jerky created using modern fermentation technology. The results show that the optimal addition amounts of camel fermented jerky ingredients are 2.2% black pepper, 3% salt, 1.8% white sugar, and 9% cooking wine, whereas the optimal fermentation conditions by compound starter culture are 0.07% starter, 23 h of fermentation time, and a 30°C fermentation temperature. Compared to the single starter, the compound starter significantly increased the protein content, total amino acids, unsaturated fatty acids, trace elements, and a *, L *, and e -values of jerky; however, it also decreased the water activity ( a w ), thiobarbituric acid, and pH values of jerky during storage. Compound starter strains can compensate for the shortage of single starters and improve the overall quality of meat products. These findings could provide new insights and serve as a reference for the development of camel meat products and hold significant importance for the growth of the camel industry., Competing Interests: None., (© 2024 The Author(s). Food Science & Nutrition published by Wiley Periodicals LLC.)

Human breast milk contains lactic acid bacteria (LAB), which have an important influence on the composition of the intestinal microbia of infants. In this study, one strain of an α-hemolytic species of the genus Streptococcus , IMAU99199 T , isolated from the breast milk of a healthy nursing mother in Hohhot city PR China, was studied to characterise its taxonomic status using phenotypic and molecular taxonomic methods. The results indicated that it represented a member of the mitis-suis clade, pneumoniae subclade of the genus Streptococcus . It is a Gram-stain-positive, catalase-negative and oxidase-negative bacterium, and the cells are globular, paired or arranged in short chains. The results of a phylogenetic analysis of its 16S rRNA gene and two housekeeping genes ( gyrB and rpoB ) placed it in the genus Streptococcus . A phylogenetic tree based on 135 single-copy genes sequences indicated that IMAU99199 T formed a closely related branch well separated from ' Streptococcus humanilactis ' IMAU99125, ' Streptococcus bouchesdurhonensis ' Marseille Q6994, Streptococcus mitis NCTC 12261 T , ' Streptococcus vulneris ' DM3B3, Streptococcus toyakuensis TP1632 T , Streptococcus pseudopneumoniae ATCC BAA-960 T and Streptococcus pneumoniae NCTC 7465 T . IMAU99199 T and ' S. humanilactis ' IMAU99125 had the highest average nucleotide identity (93.7 %) and digital DNA-DNA hybridisation (55.3 %) values, which were below the accepted thresholds for novel species. The DNA G+C content of the draft genome of IMAU99199 T was 39.8 %. The main cellular fatty acids components of IMAU99199 T were C 16 : 0 and C 16 : 1 ω7. It grew at a temperature range of 25-45 °C (the optimum growth temperature was 37 °C) and a pH range of 5.0-8.0 (the optimum growth pH was 7.0). These data indicate that strain IMAU99199 T represents a novel species in the genus Streptococcus , for which the name Streptococcus hohhotensis sp. nov. is proposed. The type strain is IMAU99199 T (=GDMCC 1.1874 T =KCTC 21155 T ).

(1) Background: Bifidobacterium plays a pivotal role within the gut microbiota, significantly affecting host health through its abundance and composition in the intestine. Factors such as age, gender, and living environment exert considerable influence on the gut microbiota, yet scant attention has been directed towards understanding the specific effects of these factors on the Bifidobacterium population. Therefore, this study focused on 98 adult fecal samples to conduct absolute and relative quantitative analyses of bifidobacteria. (2) Methods: Using droplet digital PCR and the PacBio Sequel II sequencing platform, this study sought to determine the influence of various factors, including living environment, age, and BMI, on the absolute content and biodiversity of intestinal bifidobacteria. (3) Results: Quantitative results indicated that the bifidobacteria content in the intestinal tract ranged from 10 6 to 10 9 CFU/g. Notably, the number of bifidobacteria in the intestinal tract of the school population surpassed that of the off-campus population significantly ( p = 0.003). Additionally, the group of young people exhibited a significantly higher count of bifidobacteria than the middle-aged and elderly groups ( p = 0.041). The normal-weight group displayed a significantly higher bifidobacteria count than the obese group ( p = 0.027). Further analysis of the relative abundance of bifidobacteria under different influencing factors revealed that the living environment emerged as the primary factor affecting the intestinal bifidobacteria structure ( p = 0.046, R 2 = 2.411). Moreover, the diversity of bifidobacteria in the intestinal tract of college students surpassed that in the out-of-school population ( p = 0.034). This was characterized by a notable increase in 11 strains, including B. longum , B. bifidum , and B. pseudolongum , in the intestinal tract of college students, forming a more intricate intestinal bifidobacteria interaction network. (4) Conclusions: In summary, this study elucidated the principal factors affecting intestinal bifidobacteria and delineated their characteristics of intestinal bifidobacteria in diverse populations. By enriching the theory surrounding gut microbiota and health, this study provides essential data support for further investigations into the intricate dynamics of the gut microbiota.

Chronic diarrhea has a considerable impact on quality of life. This randomized, double-blind, placebo-controlled crossover intervention trial was conducted with 69 participants (36 in Group A, 33 in Group B), aiming to investigate the potential of postbiotics in alleviating diarrhea-associated symptoms. Participants received postbiotic Probio-Eco® and placebo for 21 days each in alternating order, with a 14-day washout period between interventions. The results showed that postbiotic intake resulted in significant improvements in Bristol stool scale score, defecation frequency, urgency, and anxiety. Moreover, the postbiotic intervention increased beneficial intestinal bacteria, including Dysosmobacter welbionis and Faecalibacterium prausnitzii , while reducing potential pathogens like Megamonas funiformis . The levels of gut Microviridae notably increased. Non-targeted metabolomics analysis revealed postbiotic-driven enrichment of beneficial metabolites, including α-linolenic acid and p-methoxycinnamic acid, and reduction of diarrhea-associated metabolites, including theophylline, piperine, capsaicin, and phenylalanine. Targeted metabolomics confirmed a significant increase in fecal butyric acid after postbiotic intervention. The levels of aromatic amino acids, phenylalanine and tryptophan, and their related metabolites, 5-hydroxytryptophan and kynurenine, decreased after the postbiotic intervention, suggesting diarrhea alleviation was through modulating the tryptophan-5-hydroxytryptamine and tryptophan-kynurenine pathways. Additionally, chenodeoxycholic acid, a diarrhea-linked primary bile acid, decreased substantially. In conclusion, postbiotics have shown promise in relieving chronic diarrhea.

Lactobacillus acidophilus strains have limiting factors such as low cell density and complex nutritional requirements in industrial production, which greatly restricts their industrial application. In this study, fermentation conditions for L. acidophilus were optimized and transcriptomic analysis used to understand growth mechanisms under high-density fermentation conditions. We found that L. acidophilus IMAU81186 has strong tolerance to gastrointestinal juice. In addition, its optimal culture conditions were 3% inoculum ( v / v ); culture temperature 37 °C; initial pH 6.5; and medium composition of 30.18 g/L glucose, 37.35 g/L soybean peptone, 18.68 g/L fish peptone, 2.46 g/L sodium citrate, 6.125 g/L sodium acetate, 2.46 g/L K 2 HPO 4 , 0.4 g/L MgSO 4 ·7H 2 O,0.04 g/L MnSO 4 ·5H 2 O, 0.01 g/L serine, and 0.3 g/L uracil. After optimization, viable counts of IMAU81186 increased by 7.03 times. Differentially expressed genes in IMAU81186 were analyzed at different growth stages using transcriptomics. We found that a single carbon source had limitations in improving the biomass of the strain, and ter P and bfr A were significantly down-regulated in the logarithmic growth period, which may be due to the lack of extracellular sucrose. After optimizing the carbon source, we found that adding 12 g/L sucrose to the culture medium significantly increased cell density.

Lactobacillus kefiranofaciens is often found in fermented dairy products. Many strains of this species have probiotic properties, contributing to the regulation of immune metabolism and intestinal flora. This species was added to the list of lactic acid bacteria that can be added to food in China, in 2020. However, research on the genomics of this species is scarce. In this study we undertook whole genome sequencing analysis of 82 strains of L. kefiranofaciens from different habitats, of which 9 strains were downloaded from the NCBI RefSeq (National Center for Biotechnology Information RefSeq). The mean genome size of the 82 strains was 2.05 ± 0.25 Mbp, and the mean DNA G + C content was 37.47 ± 0.42%. The phylogenetic evolutionary tree for the core genes showed that all strains belonged to five clades with clear aggregation in relation to the isolation habitat; this indicated that the genetic evolution of L. kefiranofaciens was correlated to the isolation habitat. Analysis of the annotation results identified differences in the functional genes, carbohydrate active enzymes (CAZy) and bacteriocins amongst different isolated strains, which were related to the environment. Isolates from kefir grains had more enzymes for cellulose metabolism and a better ability to use vegetative substrates for fermentation, which could be used in feed production. Isolates from kefir grains also had fewer kinds of bacteriocin than isolates from sour milk and koumiss; helveticin J and lanthipeptide class I were not found in the isolates from kefir grains. The genomic characteristics and evolutionary process of L. kefiranofaciens were analyzed by comparative genomics and this paper explored the differences in the functional genes amongst the strains, aiming to provide a theoretical basis for the research and development of L. kefiranofaciens .

According to the United Nations population profile, the number of individuals aged 60 and over in high-income nations is expected to rise from 302 million to over 366 million between 2019 and 2030, so there is an increasing emphasis on nutrition and health in older people. Numerous studies have demonstrated the crucial role that gut microbiota plays in maintaining human health. As a model of healthy aging, centenarians have different gut microbiota from ordinary elderly people. The core microbiome of centenarians in various countries has shown some common characteristics, which are worth further exploration. In this review, the significance of the human gut microbiota to health is briefly discussed, and the characteristics of the gut microbiota of long-lived senior persons of different ages and in different countries are described. Moreover, this review lists dietary interventions and fecal microbiota transplantation. In the end, it discusses the pros and cons of using probiotics to enhance the health of seniors through focused management of the gut microbiota. It aims to pave the way for further investigation into the nexus between gut microbiota, probiotics, and longevity, and then to reveal the underlying mechanism to promote longevity. KEY POINTS: • Gut microbial structure in different age groups and the characteristics of gut microbiota in centenarians. • Dietary interventions, fecal transplants, and probiotics target the modulation of gut microbiota for healthy aging., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Fifty-seven strains of Lactobacillus were isolated from fecal samples of healthy young people in Tibet, Xinjiang, and Inner Mongolia using pure culture methods. Lactobacillus ruminis and Lactobacillus gasseri were the dominant Lactobacillus species isolated from the intestinal microflora, accounting for 54.4% and 14.0% of the total isolates, respectively. Isolated strains were identified by 16S rRNA sequencing, and their tolerance to gastric acid and bile salt, and fermentation characteristics were evaluated. The results of experiments in vitro showed that nine of the isolated strains of Lactobacillus grew well at pH 3.0. After 11 h of incubation in artificial digestive juices, the isolated L. plantarum and the control strain L. plantarum P8 still had high survival rates. Most of the isolates and control isolates have strong tolerance to bile salts. The evaluation of fermentation characteristics indicated that the ability of the intestinal Lactobacillus to ferment skimmed milk was lower than that of the reference L. plantarum P8. In the process of storage, the viable count of screened isolates of human origin in fermented milk decreased to some extent, but remained above 7.01 ± 0.22 log CFU/ml, showing good storage characteristics., (© 2021 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)