Co-fermented cow milk protein by Lactobacillus helveticus KLDS 1.8701 and Lactobacillus plantarum KLDS 1.0386 attenuates its allergic immune response in Balb/c mice.

Milk protein is one of the major food allergens. As an effective processing method, fermentation may reduce the potential allergenicity of allergens. This study aimed to evaluate the therapeutic potential of co-fermented milk protein using Lactobacillus helveticus KLDS 1.8701 and Lactobacillus plantarum KLDS 1.0386 in cow milk protein allergy (CMPA) management. This study determined the secondary and tertiary structures of the fermented versus unfermented proteins by Fourier-transform infrared spectroscopy and surface hydrophobicity to evaluate its conformational changes. Our results showed that different fermentation methods have significantly altered the conformational structures of the cow milk protein, especially the tertiary structure. Further, the potential allergenicity of the fermented cow milk protein was assessed in Balb/c mice, and mice treated with the unfermented milk and phosphate-buffered saline were used as a control. We observed a significant reduction in allergenicity via the results of the spleen index, serum total IgE, specific IgE, histamine, and mouse mast cell protease 1 in the mice treated with the co-fermented milk protein. In addition, we analyzed the cytokines and transcription factors expression levels of spleen and jejunum and confirmed that co-fermentation could effectively reduce the sensitization of cow milk protein by regulating the imbalance of T helper (Th1/Th2 and Treg/Th17). This study suggested that changes of conformational structure could reduce the potential sensitization of cow milk protein; thus, fermentation may be a promising strategy for developing a method of hypoallergenic dairy products.

Infant formula supplemented with 1,3-olein-2-palmitin regulated the immunity, gut microbiota, and metabolites of mice colonized by feces from healthy infants.

Infant formula is currently an important food to cope with insufficient breastfeeding. Although 1,3-olein-2-palmitin (OPO) has been used in infant formula, its effects on the immune system, gut microbiota, and metabolites for infants remain unclear. This study constructed a mouse model of colonizing healthy infant feces using antibiotic treatment and fecal microbial transplantation. Thus, the gap between the infant formula supplemented with OPO and human milk in mouse serum biochemistry, immune system, intestinal microbiota, short-chain fatty acid production, and metabolites was evaluated. Our results showed that regarding IL-9, IL-10 levels, fecal secretory IgA, and endotoxin, formula supplemented with OPO and human milk types had comparable levels. Additionally, OPO slightly increased the content of short-chain fatty acids. The 16S rRNA gene sequence analysis and metabonomics analysis demonstrated that feeding different foods affects the gut microbiota of mice; in particular, supplementing formula feeding with OPO enriched the abundance of bifidobacteria. Furthermore, feeding different foods leads to unique intestinal content of metabolites, and the gut microbiota regulates the metabolites' differences. Our results reveal a brand new perspective of OPO regarding gut microbiota and metabolites.

Proteolytic activities of combined fermentation with Lactobacillus helveticus KLDS 1.8701 and Lactobacillus plantarum KLDS 1.0386 reduce antigenic response to cow milk proteins.

Cow milk protein is one of the leading food allergens. This study aimed to develop an effective method for reducing milk sensitization by evaluating antigenicity of fermented skim milk protein using Lactobacillus helveticus KLDS 1.8701, Lactobacillus plantarum KLDS 1.0386, and a combination of both strains. The proteolytic systems of strains in terms of genotype and phenotype are characterized by complete genome sequence, and evaluation the antigenicity of skim milk proteins was determined by ELISA and liquid chromatography with tandem mass spectrometry. Our results showed that the genomes encoded a variety of peptidase genes. For fermented skim milk, the degree of hydrolysis of the combined strains was higher than that of individual strain. Electrophoresis showed that the band color density of α-casein (α-CN) by fermentation of the combined strains was reduced when compared with control group. The fermentation process of the combined strains inhibited α-CN, ß-lactoglobulin, and α-lactalbumin antigenicity by 69.13, 36.10, and 20.92, respectively. Major allergic epitopes of α-CN and ß-lactoglobulin were cleaved by abundant proteases of combined strains. In all, this study showed that the fermentation process involving both L. helveticus and L. plantarum strains could reduce cow milk protein allergenicity through the combination of cell-envelope proteinase and peptidase on α-CN.

Milk fat globule membrane regulates the physicochemical properties and surface composition of infant formula powders by improving the stability of the emulsion.

The milk fat globules in infant formula (IF) are encapsulated by a component known as milk fat globule membrane (MFGM). However, it is currently unclear whether the improved emulsion stability of MFGM can have a profound effect on the finished IF. Therefore, this study investigated the effects of MFGM on the particle size, stability, rheology, and microstructure of emulsions prepared by dairy ingredients via wet mixing. Further, IF were processed using such emulsions, the physicochemical properties, surface composition of the powders were examined. The results showed that MFGM reduced the particle size of the emulsion, increased the viscosity, and improved the microstructure of the MFGM. Furthermore, MFGM reduced the moisture content of the powder, increased the glass transition temperature, and reduced the presence of surface fat. In conclusion, the addition of MFGM enhance the finished powder stability by improving the emulsion stability prepared during IF manufacturing.

Elucidating gut microbiota and metabolite patterns shaped by goat milk-based infant formula feeding in mice colonized by healthy infant feces.

The gut microbiota plays an evolutionarily conserved role in host metabolism, which is influenced by diet. Here, we investigated differences in shaping the gut microbiota and regulating metabolism in cow milk-based infant formula, goat milk-based infant formula, and mix milk-based infant formula compared with pasteurized human milk. 16S rRNA results showed that goat milk-based infant formula selectively increased the relative abundance of Blautia, Roseburia, Alistites and Muribaculum in the gut compared to other infant formulas. Metabolomics identification indicated that goat milk-based infant formula mainly emphasized bile acid biosynthesis, arachidonic acid metabolism and steroid biosynthesis metabolic pathways. Metabolites associated with these metabolic pathways were positively associated with increased microorganisms in goat milk-based infant formula, particularly Alistipes. Furthermore, we found a deficiency of Akkermansia abundance in three infant formula-fed compared to pasteurizedhuman milk-fed. This study presents new insights into the improvement and application of goat milk-based infant formulas in terms of intestinal microecology.

Antibiotic Conditioning Shapes Pseudosterile Mouse Models by Deleting Colonic Microbes Rather than Small Intestinal Microbes.

A simple model of alternative microbiota in the developing intestinal environment has been highly desirable for the study of health and disease in the gut. The pattern of antibiotic depletion of natural gut microbes is necessary for this model. However, the effects and loci of antibiotic deletion of gut microbes remain unclear. In this study, a mixture of three proven broad-spectrum antibiotics was selected to study their effects on microbial deletions in the jejunum, ileum, and colon of mice. The 16S rRNA sequencing results showed that antibiotics significantly reduced colonic microbial diversity, with limited effects on the jejunum and ileum. At the level of microbial genera, only 93.38% of Burkholderia-Caballeronia-Paraburkholderia and 5.89% of Enterorhabdus were present in the colon after antibiotic treatment. However, such changes were not observed in the microbial composition of the jejunum and ileum. Our results suggest that the antibiotics depleted intestinal microorganisms by acting primarily in the colon and not in the small intestine (jejunum and ileum). IMPORTANCE Many studies have applied antibiotics to delete intestinal microbes to shape pseudosterile mouse models and further used for fecal microbial transplantation. However, few studies have explored the spatial location of antibiotic action in the intestine. This study shows that the selected antibiotics effectively deleted microbiota in the colon of mice, with limited effects on microbes in the jejunum and ileum. Our study provides guidance for the application of a mouse model of antibiotic deletion of intestinal microbes.

2'-Fucosyllactose Promotes the Production of Short-Chain Fatty Acids and Improves Immune Function in Human-Microbiota-Associated Mice by Regulating Gut Microbiota.

As a natural prebiotic in human milk, 2'-fucosyllactose (2'-FL) is actively used in infant formula (IF). However, the 2'-FL influence on the improvement of gut microbiota and the regulation of the immune function remains unknown. In this study, human microbiota-associated (HMA) mice were used to demonstrate that feeding 2'-FL-containing IF was comparable to human milk at levels of immune cytokines (IL-2, IL-9, IL-10, and sIgA) and short-chain fatty acids (SCFAs, i.e., acetate and propionate). In addition, 2'-FL increased the abundance of Blautia and Olsenella and improved the anti-inflammatory cytokine IL-10 levels. The abundance of Blautia and Olsenella positively correlated with the IL-10 levels. 2'-FL also decreased the abundance of Enterorhabdus and Lachnospiraceae_UCG-006 and elevated SCFA levels, showing a negative correlation between these genera and SCFAs. Our findings revealed that feeding 2'-FL-containing IF drives the levels of cytokines and SCFAs toward human milk levels by shaping the beneficial gut microbiota profile.

Elucidating the physicochemical properties and surface composition of goat milk-based infant formula powders.

This study investigated the characteristics of cow milk-based, goat milk-based, and mixed-based (using goat milk and cow whey powder)infant formulas (IF) with different sources of casein and whey protein, aiming to construct the properties of powders prepared using goat milk. Goat milk-based IF have different water activity, color, and glass transition temperature than other IF, whereas the crystallinity and solubility were similar. SDS-PAGE pattern showed that goat milk-based and mixed-based IF contained higher ß-casein, while cow milk-based IF contained higher αs1-casein. The differentials of casein affected the powder surface composition and free fat levels. Goat milk-based IF reduces the surface fat content and free fat levels of the particles. Further analysis showed that the surface of the particles was predominantly filled with saturated fatty acids. Our findings revealed that due to the different casein, goat milk-based IF have favorable characteristics and surface composition, thus promoting its particle stability.

In vivo evidence of the prevents DSS-induced colitis of Lactiplantibacillus plantarum L15.

Ulcerative colitis (UC) is challenging to treat and severely impacts patients and families. A previous study reported immunomodulatory and reduction of pro-inflammatory properties for the Lactiplantibacillus plantarum L15. This study aimed to analyze the preventive properties and mechanistic actions in an in vivo colitis model. The histopathological alteration, inflammation cytokines, and intestinal barrier function were analyzed. Subsequently, the cecal gut microbiota contents and products from different groups were detected. Finally, gene expressions related to the NF-κB signaling process were evaluated. L. plantarum L15 significantly decreased disease activity index (DAI), myeloperoxidase activity (MPO), pro-inflammatory cytokine (TNF-α, IL-1ß, and IL-6) level, and increased weight change, colon length, and production of inflammation-suppressing cytokines. Furthermore, this strain supplementation substantially increased ZO-1, Occludin, and Claudin-1, and MUC2 mRNA expression levels with a corresponding decrease in serum lipopolysaccharide and D-lactic acid contents. In addition, L. plantarum L15 improved gut microbiota composition and increased short-chain fatty acid (SCFAs) in the colon content, which significantly reduced the transfer of NF-κB p65 to the nucleus. Our findings provide a theoretical basis for L. plantarum L15 as a preventive candidate for UC.

Distinct gut microbiota and metabolite profiles induced by delivery mode in healthy Chinese infants.

Delivery mode is recognized as an important determinant of gut microbiota composition. Vaginally delivered infants were colonized by maternal vaginal and fecal microbiota, while those delivered by cesarean section were colonized by environmental microorganisms. To reveal differences induced by delivery mode, we determined fecal microbiota and fecal metabolome from 60 infants in Northeast China region. Bacterial gene sequence analysis showed that the feces of vaginally delivered infants had the highest abundance of Bifidobacterium, Lactobacillus, Bacteroides and Parabacteroides, while the feces of cesarean section delivered infants were more enriched in Klebsiella. LC-MS-based metabolomics data demonstrated that the feces of vaginally delivered infants were associated with high abundance of DL-norvaline and DL-citrulline, while the feces of cesarean section delivered infants were abundant in trans-vaccenic acid and cis-aconitic acid. Moreover, the feces of vaginally delivered infants was significantly in positive correlation with tryptophan metabolism and pyruvate metabolism, however, the feces of cesarean section delivered infants was positively correlated with ABC transporters. Collectively, our study demonstrated that gut microbiota and metabolite profiles were significantly different between vaginally delivered and cesarean section delivered infants, and provided the theoretical basis for restoring the intestinal environment of cesarean section infants birthed in the study region. SIGNIFICANCE: The intestinal microbiota and metabolites play important roles in infant development. To validate whether delivery modes influence the gut environment, we performed a detailed analysis of the earliest microbial colonization of the infant gut using a combination of 16S rRNA gene amplicon sequencing and LC-MS-based metabolomics. We found that the gut microbiota and metabolite composition were significantly different between vaginally delivered infants and cesarean section delivered infants. Our findings establish a vital baseline for studies tracking the infant gut microbiota and metabolite development following different delivery modes, and their associated effects on infant health. This study provides preliminary evidence that the observed differences due to delivery modes highlight their importance in shaping the early intestinal microbiota and metabolites.

The Protective Effects of Lactobacillus plantarum KLDS 1.0344 on LPS-Induced Mastitis In Vitro and In Vivo.

Cow mastitis, which significantly lowers milk quality, is mainly caused by pathogenic bacteria such as E. coli. Previous studies have suggested that lactic acid bacteria can have antagonistic effects on pathogenic bacteria that cause mastitis. In the current study, we evaluated the in vitro and in vivo alleviative effects of L. plantarum KLDS 1.0344 in mastitis treatment. In vitro antibacterial experiments were performed using bovine mammary epithelial cell (bMEC), followed by in vivo studies involving mastitis mouse models. In vitro results indicate that lactic acid was the primary substance inhibiting the E. coli pathogen. Meanwhile, treatment with L. plantarum KLDS 1.0344 can reduce cytokines' mRNA expression levels in the inflammatory response of bMEC induced by LPS. In vivo, the use of this strain reduced the secretion of inflammatory factors IL-6, IL-1ß, and TNF-α, and decreased the activity of myeloperoxidase (MPO), and inhibited the secretion of p-p65 and p-IκBα. These results indicate that L. plantarum KLDS 1.0344 pretreatment can reduce the expression of inflammatory factors by inhibiting the activation of NF-κB signaling pathway, thus exerting prevent the occurrence of inflammation in vivo. Our findings show that L. plantarum KLDS 1.0344 has excellent properties as an alternative to antibiotics and can be developed into lactic acid bacteria preparation to prevent mastitis disease.

Gut microbiota modulation and anti-inflammatory properties of mixed lactobacilli in dextran sodium sulfate-induced colitis in mice.

Correlations between gut microbiota activities and inflammatory bowel disease (IBD) treatment are gaining research interest. In our previous study, Lactobacillus acidophilus KLDS 1.0901, Lactobacillus helveticus KLDS 1.8701, and Lactobacillus plantarum KLDS 1.0318 showed antibacterial, antioxidant, and immunomodulatory activities. In the current study, we evaluated the effects of three tested strains and their mixture on dextran sulfate sodium (DSS)-induced colitis in C57BL/6J mice. The three tested strains and their mixture significantly decreased the disease activity index (DAI), colon shortening, and myeloperoxidase (MPO) activity. Additionally, the three tested strains and their mixture improved the histological damage, increased the colonic mucous layer integrity, and exhibited lower levels of prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6), while up-regulating colonic anti-inflammatory cytokine IL-10 levels, tight junction proteins (E-cadherin, zonulae occludens (ZO)-1, occludin and claudin-1) and mucin (MUC1 and MUC2) mRNA expressions to some extent. In addition, mixed lactobacilli showed better anti-inflammatory effects than single-strain treatment. Our study further revealed that mixed lactobacilli increased bacterial diversity and improved gut microbiota composition, increasing short-chain fatty acid (SCFA) production. These results indicated that mixed lactobacilli supplementation could attenuate DSS-induced colitis by modulating the gut microbiota and repairing the intestinal barrier, which provided a scientific basis for its clinical application in the future.

A biosensor based on multifunctional allostery for dynamic analysis of circulating tumor DNA.

Here, a new strategy based on artificial multifunctional allostery (mFA) was explored to regulate the assembly of a DNA nanowire using circulating tumor DNA (ctDNA) as the initiator. Given its unique properties, the mFA-regulated versatile DNA nanowire was applied to engineer a single-step, amplified and dynamic biosensor for the quantitative analysis of ctDNA in serum samples with tunable sensitivity and selectivity.

Cow, Goat, and Mare Milk Diets Differentially Modulated the Immune System and Gut Microbiota of Mice Colonized by Healthy Infant Feces.

Studies on the possible alternative supplements to breastmilk are gaining research interests. Although milk from cow, goat, and mare is nutritious, its effects on the relationship between the immune system, metabolites, and gut microbiota remain unclear. This study aimed to comprehensively evaluate the effects of cow, goat, and mare milk on the immune system, metabolites, and gut microbiota of mice colonized by healthy infant feces using human milk as a standard. We examined the serum biochemistry parameters, immunity indicators, T cells, gut microbiota abundance, and metabolites. Results showed that the impact of human milk on alanine transaminase, glutamic oxaloacetic transaminase, total protein, globulin, and glucose values was different from the cow, goat, and mare milk types. The effects of mare milk on the percentage of CD4+ T, Th1, Th2, Th17, and Treg cells, and the levels of IL-2, IL-4, sIgA, and d-lactic acid in the serum of the human microbiota-associated mice were comparable to those of human milk. Also, bacterial 16S rRNA gene sequence analysis revealed that human milk enriched the relative abundance of Akkermansia and Bacteroides, cow milk increased the relative abundance of Lactobacillus, goat milk increased the relative abundance of Escherichia-Shigella, and mare milk improved the relative abundance of Klebsiella. Besides, mare milk was similar to human milk in the concentration of the metabolites we analyzed. Our findings suggest that mare milk can positively modulate the gut microbiota and immunity status of infants and thus could be a possible replacement for human milk.