Precooked state based on protein denaturation kinetics impacts moisture status, protein oxidation and texture of prepared chicken breast.

The quality of meat in prepared dishes deteriorates due to excessive protein denaturation resulting from precooking, freezing, and recooking. This study aimed to link the precooked state with chicken breast's recooked quality. Cooked Value (CV), based on protein denaturation kinetics, was established to indicate the doneness of meat during pre-heating. The effects of CVs after pre-heating on recooked qualities were investigated compared to fully pre-heated samples (control). Mild pre-heating reduced water migration and loss. While full pre-heating inhibited protein oxidation during freezing, intense oxidation during pre-heating led to higher oxidation levels. Surface hydrophobicity analysis revealed that mild pre-heating suppressed aggregation during recooking. These factors contributed to a better texture and microstructure of prepared meat with mild pre-heating. Finally, a potential mechanism of how pre-heating affects final qualities was depicted. This study underlines the need for finely controlling the industrial precooking process to regulate the quality of prepared meat.

Unveiling the therapeutic potential and mechanism of inulin in DSS-induced colitis mice.

Inulin has been reported to alleviate colitis. In this study, colitis patients' feces were used to simulate fermentation to demonstrate changes in the microbiota profile in the presence of inulin. We found inulin can reshape the gut microbiota profile of colitis patients, especially by altering the abundance of Faecalibacterium and Blautia. Interestingly, the subsequent co-culture with inulin demonstrated that inulin promoted the growth of these two strains of bacteria. The dextran sodium sulfate (DSS)-induced mouse model was used to examine the effect of inulin and its combination with two probiotics on colitis. Results showed that all three treatments can alleviate the clinical symptoms, including weight-losing, colon-shortening, and the Disease Activity Index (DAI) score. Further investigations showed that the administrations regulate colitis mice's pro- and anti-inflammatory cytokines, such as TNF-α, IL-1ß, IL-6, IL-10, and IL-17. Also, they alter the relative abundance of Faecalibacterium and Blautia, change the short-chain fatty acids (SCFAs) profile in the cecum and colon, and improve the intestinal barrier; specifically, the intervention increased the expressions of Claudin, Occludin, Zonula Occludens (ZO)-1, and Mucin (MUC)-2 in colonic tissues, thus restoring the colonic tissue structure and morphology of colitis mice. Collectively, our results confirm that inulin can alter the colitis patients' characteristic microbial community, and they can ameliorate experimental colitis by inhibiting the TRL4/MyD88/NF-κB signaling pathway-improving the inflammatory response and enhancing the intestinal barrier. In conclusion, we propose that inulin may hold promise as a functional food therapeutic approach for the treatment of colitis.

Lead toxicity mitigation effect of a Lactiplantibacillus plantarum-chondroitin sulfate complex revealed by microbiome and metabolomic analyses.

Lead (Pb) is a highly toxic metal with no physiological function in humans, accumulates in the body through food intake, and causes gut microbiome disorders and other hazards. In the present study, we examined the efficacy of a combination of chondroitin sulfate and Lactiplantibacillus plantarum CCFM8661 (CCFM8661 + CS) on tissue Pb accumulation and pathological damage to the liver and kidneys, gut microbiota, and fecal metabolites in Pb-exposed mice. Oral administration of CCFM8661 + CS to Pb-exposed mice reduced Pb accumulation in the liver, kidney, and bone tissues (from 3.70, 14.11 and 121.20 mg g-1 wet tissue to 2.26, 8.72 and 65.57 mg g-1 wet tissue, respectively) and increased total antioxidant capacity, superoxide dismutase, and glutathione in the liver and kidneys. Additionally, gut microbiome analysis showed that CCFM8661 + CS intervention attenuated Pb-induced perturbation in gut microbiota, altering the abundance of bacteria such as Faecalibaculum, Ruminococcaceae UCG 014, Anaerostipes, and Enterorhabdus. Untargeted metabolomics analyses showed that CCFM8661 + CS significantly increased cinnamoylglycine, hippuric acid, and equol (to 31.24, 28.77 and 20.13 times the baseline, respectively) and decreased guanine and 4-coumaric acid (0.30 and 0.09 times the baseline, respectively) in the feces, affecting pathways such as purine and amino acid metabolism. Further analyses showed that promoting Pb excretion and restoring the Pb-impaired gut microbiome and its metabolism may be important contributors to CCFM8661 + CS alleviation of Pb toxicity.

The alleviative effects of viable and inactive Lactobacillus paracasei CCFM1120 against alcoholic liver disease via modulation of gut microbiota and the Nrf2/HO-1 and TLR4/MyD88/NF-κB pathways.

Probiotics can alleviate alcoholic liver disease. However, whether inactive counterparts can produce similar outcomes requires further investigation. We investigated the effects of viable (V) and dead (D) Lactobacillus paracasei CCFM1120 on alcohol-induced ALD mice. The results showed that CCFM1120V and D ameliorated the disease symptoms and intestinal injury. Specifically, these interventions strengthened the intestinal barrier, as evidenced by the increased expression of ZO-1 (zonula occludens 1), occludin, and claudin-1 in the colon and the restored ileal microstructure, including the villi and crypts. In addition, they enhanced the antioxidant capacity of the liver by reducing the production of malondialdehyde and increasing the levels of glutathione and superoxide dismutase. The activation of Nrf2 and HO-1 may be responsible for recovering the antioxidant capacity. Interventions can decrease mouse TNF-α, IL-6 and IL-1ß content in serum, probably through the TLR4/MyD88/NF-κB pathway. Furthermore, they possess the ability to restore the quantities of bacteria responsible for producing butyric acid, such as Lactobacillus, Blautia, Bifidobacterium, Ruminococcaceae, Faecalibaculum and Lachnospiraceae. Taken together, CCFM1120V and D apparently can modify the composition of the gut microbiota, foster the gastrointestinal equilibrium, fortify the intestinal barrier, augment the antioxidant capacity of the liver, and effectively shield it from ethanol-induced injury.

Bifidobacterium animalis subsp. lactis CCFM1274 relieved allergic asthma symptoms by modifying intestinal tryptophan metabolism in mice.

Approximately two-thirds of patients with asthma, a common inflammatory airway disease, are thought to present with allergies. Probiotics and tryptophan metabolites are becoming increasingly important in treating allergic asthma. This study aimed to identify potential probiotic strains and tryptophan metabolites that could alleviate asthma symptoms. Based on in vitro fermentation experiments, we evaluated variations in probiotic capacity to metabolize tryptophan. Of the eight tested strains, Bifidobacterium animalis subsp. lactis CCFM1274 produced relatively high levels of indole-3-carboxaldehyde (I3C). A mouse model of allergic asthma was established by oral administration of ovalbumin (OVA) and was subjected to oral administration of probiotics. The results demonstrated that treatment with CCFM1274 reduced the tendency for body weight loss and mortality in OVA-induced asthmatic mice. Ingestion of CCFM1274 improved the infiltration of perivascular and peribronchial inflammatory cells in the lung sections stained with hematoxylin and eosin (H&E). This outcome was accompanied by a reduction in the serum levels of OVA-specific immunoglobulin E (OVA-sIgE) and in the levels of IL-10 and IL-17 in the bronchoalveolar lavage fluid (BALF). The linear discriminant analysis effect size (LEfSe) of the gut microbiota showed that CCFM1274 increased the relative abundance of Bifidobacterium. In conclusion, CCFM1274 remodeled intestinal tryptophan metabolism in mice and contributed to the improvement of allergic asthma.

Lactobacillus plantarum Ameliorates Colorectal Cancer by Ameliorating the Intestinal Barrier through the CLA-PPAR-γ Axis.

Colorectal cancer (CRC) is the third-largest cancer worldwide. Lactobacillus can regulate the intestinal barrier and gut microbiota. However, the mechanisms of Lactobacillus that alleviate CRC remained unknown. This study aimed to explore the regulatory effect of Lactobacillus plantarum on CRC and its potential mechanism. CCFM8661 treatment significantly ameliorated CRC compared with phosphate-buffered solution (PBS) treatment in ApcMin/+ mice. In addition, conjugated linoleic acid (CLA) was proved to be the key metabolite for CCFM8661 in ameliorating CRC by molecular biology techniques. Peroxisome proliferator-activated receptor γ (PPAR-γ) was proved to be the key receptor in ameliorating CRC by inhibitor intervention experiments. Moreover, supplementation with CCFM8661 ameliorated CRC by producing CLA to inhibit NF-κB pathway and pro-inflammatory cytokines, up-regulate ZO-1, Claudin-1, and MUC2, and promote tumor cell apoptosis in a PPAR-γ-dependent manner. Metagenomic analysis showed that CCFM8661 treatment significantly increased Odoribacter splanchnicus, which could ameliorate CRC by repairing the intestinal barrier. Clinical results showed that intestinal CLA, butyric acid, PPAR-γ, and Lactobacillus were significantly decreased in CRC patients, and these indicators were significantly negatively correlated with CRC. CCFM8661 alleviated CRC by ameliorating the intestinal barrier through the CLA-PPAR-γ axis. These results will promote the development of dietary probiotic supplements for CRC.

Tracking Childhood Lead Exposure in Early Industrial Romanians.

Childhood lead exposure has been linked to severe adverse health outcomes throughout life. Measurements of lead in teeth have established that individuals living in contaminated environments show higher levels compared to individuals living further away, although less is known about when individuals are most susceptible to these exposures. We examined lead (Pb208) concentrations (ppm) in teeth over the first 2.5 years of life in 16 children born in the late 19th to early 20th century throughout Romania. This period of intense industrialization was characterized by increases in mining, coal burning, and oil refining-activities that contaminate air, water, and food with Pb. We hypothesized the distance from an operational mine or oil refinery, or being born in a city, would be positively associated with cumulative dentine Pb exposure (CDPE). We also predicted that Pb exposures would peak in the first six months of life when gastrointestinal (GI) absorption of Pb is likely highest. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) of sectioned tooth dentine followed by Bayesian statistical analyses revealed that living 30 km or more from a mine or oil refinery did not explain CDPE. However, being born in a city explained 42% of CDPE. All individuals showed maximum Pb exposures after six months of age, likely due to contaminated solid food and/or non-milk liquids. This research demonstrates how tooth formation can be coupled with comprehensive elemental mapping to analyse the context and timing of early-life neurotoxicant exposures, which may be extended to well-preserved teeth from clinical and historic populations.

The therapeutic effect of levosimendan in patients with prolonged ventilator weaning and cardiac dysfunction.

OBJECTIVE: To explore the therapeutic effect of levosimendan in patients with prolonged ventilator weaning and cardiac dysfunction. METHOD: Patients with prolonged ventilator weaning and cardiac dysfunction were randomly allocated to receive conventional treatment (control group) or intravenous infusion of levosimendan for 24 h based on conventional treatment (levosimendan group). Weaning success rates were then compared between the two groups. The study was retrospectively registered with Research Registry (ID No. researchregistry10304). RESULTS: A total of 40 patients were included (20 per group). Within 3 days after initiation of treatment, significantly more cases were successfully weaned in the levosimendan group versus control group (eight versus four cases, respectively). Among the eight patients who underwent pulse indicator continuous cardiac output monitoring in the levosimendan group, the global ejection fraction increased 24 h after treatment, and the cardiac function index and cardiac index increased 72 h after treatment. CONCLUSION: For patients requiring prolonged mechanical ventilation who have concomitant cardiac dysfunction, levosimendan may be considered to increase the probability of weaning success.

Imaging Mass Spectrometry and Genome Mining Reveal Antimicrobial Peptides of Novel Pediococcus acidilactici CCFM18.

The mechanism of metabolites produced by lactic acid bacteria in mediating microbial interactions has been difficult to ascertain. This study comparatively evaluated the antimicrobial effect of the novel bacterium Pediococcus acidilactici CCFM18 and explored the global chemical view of its interactions with indicator bacteria. P. acidilactici CCFM18 had sufficiently strong antimicrobial activity to effectively inhibit the growth of the indicator bacteria and enhance their intracellular reactive oxygen species (ROS) level. The emerging technique of matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) imaging mass spectrometry indicated that P. acidilactici CCFM18 increased the production of pediocin PA-1 and the penocin A profile during its interaction with the indicator bacteria, thus differing from P. acidilactici CCFM28 (a commonly used laboratory strain). Strikingly, the production of coagulin A was triggered only by signaling molecules made by the competing strain L. thermophilus, suggesting an idiosyncratic response from P. acidilactici CCFM18. Bioinformatic mining of the P. acidilactici CCFM18 draft genome sequence revealed gene loci that code for the complex secondary metabolites analyzed via MSI. Taken together, these results illustrate that chemical interactions between P. acidilactici CCFM18 and indicator bacteria exhibit high complexity and specificity and can drive P. acidilactici CCFM18 to produce different secondary metabolites.

Effects of Lactiplantibacillus plantarum CCFM1214 and Ligilactobacillus salivarius CCFM1215 on halitosis: a double-blind, randomized controlled trial.

The purpose of this study was to evaluate the effects of known probiotic species Lactiplantibacillus plantarum CCFM1214 and Ligilactobacillus salivarius CCFM1215 on halitosis, the oral status, and the oral microbiome. In a double-blind, randomized controlled trial that lasted for five weeks, 43 participants were divided into an oral probiotics group and a control group and given probiotics or control powder for the first four weeks, with the fifth week being the discontinuation period. 33 participants (probiotics group = 21, control group = 12) completed the entire experiment in the end. Oral samples were taken as part of oral health examinations during the baseline period (day 0) and four weeks after (day 28). The nucleotide sequence of the V3-V4 region of 16S rRNA was determined to examine the impact of intervention and time on the oral microbiome. The effects of L. plantarum CCFM1214 and L. salivarius CCFM1215 on the number of Fusobacterium nucleatum in gingival crevicular fluid (GCF) samples of participants were detected by quantitative PCR. After the intervention, L. plantarum CCFM1214 and L. salivarius CCFM1215 significantly reduced the levels of volatile sulfur compounds (VSCs) and the quantity of F. nucleatum in GCF samples, where the average DNA copy number per ng (log) of F. nucleatum decreased from 7.12 ± 0.04 to 6.01 ± 0.09. The ß diversity of the probiotics group, on the whole, tended to be more concentrated and stable after the intervention. In addition, after probiotic intervention, the abundance of Lactobacillus and Bifidobacterium increased, while the abundance of Fusobacterium, Acinetobacter, Porphyromonas, and Aggregatibacter decreased significantly. In general, L. plantarum CCFM1214 and L. salivarius CCFM1215 can alleviate halitosis and considerably lower the value of VSCs and improve the oral microbiota in participants with halitosis.

O-glycosylation in viruses: A sweet tango.

O-glycosylation is an ancient yet underappreciated protein posttranslational modification, on which many bacteria and viruses heavily rely to perform critical biological functions involved in numerous infectious diseases or even cancer. But due to the innate complexity of O-glycosylation, research techniques have been limited to study its exact role in viral attachment and entry, assembly and exit, spreading in the host cells, and the innate and adaptive immunity of the host. Recently, the advent of many newly developed methodologies (e.g., mass spectrometry, chemical biology tools, and molecular dynamics simulations) has renewed and rekindled the interest in viral-related O-glycosylation in both viral proteins and host cells, which is further fueled by the COVID-19 pandemic. In this review, we summarize recent advances in viral-related O-glycosylation, with a particular emphasis on the mucin-type O-linked α-N-acetylgalactosamine (O-GalNAc) on viral proteins and the intracellular O-linked ß-N-acetylglucosamine (O-GlcNAc) modifications on host proteins. We hope to provide valuable insights into the development of antiviral reagents or vaccines for better prevention or treatment of infectious diseases.

Cross-feeding of bifidobacteria promotes intestinal homeostasis: a lifelong perspective on the host health.

Throughout the life span of a host, bifidobacteria have shown superior colonization and glycan abilities. Complex glycans, such as human milk oligosaccharides and plant glycans, that reach the colon are directly internalized by the transport system of bifidobacteria, cleaved into simple structures by extracellular glycosyl hydrolase, and transported to cells for fermentation. The glycan utilization of bifidobacteria introduces cross-feeding activities between bifidobacterial strains and other microbiota, which are influenced by host nutrition and regulate gut homeostasis. This review discusses bifidobacterial glycan utilization strategies, focusing on the cross-feeding involved in bifidobacteria and its potential health benefits. Furthermore, the impact of cross-feeding on the gut trophic niche of bifidobacteria and host health is also highlighted. This review provides novel insights into the interactions between microbe-microbe and host-microbe.

Bifidobacterium longum subsp. infantis regulates Th1/Th2 balance through the JAK-STAT pathway in growing mice.

Objectives: Bifidobacterium longum subsp. infantis is a dominant bacterium in infant gut, which plays a critical role in maintaining the health and development of infants. This study investigated the abilities of eight different strains of B. longum subsp. infantis to regulate the T helper (Th)1/Th2 balance. Methods: Eight B. longum subsp. infantis strains, including I2MI (FJSWXI2MIM1), I4MI [FJSWXI4MI (CCFM1270)], I4MNI (FJSWXI4MNIM1), I5TI (FJSWXI5TIM1), I6TI (FJSWXI6TIM1), I8TI [FJSWXI8TI (CCFM1271)], I10TI [FJSWXI10TI (CCFM1272)], and B6MNI [BJSWXB6MNIM1 (CCFM1269)], were gavaged to BALB/C pups in both female (n = 8) and male (n = 8) mice starting from 1 to 3 weeks old (1 × 109 CFU/day/mice). Selected immune cells were assessed by immunofluorescence and flow cytometry. Cytokines and immunoglobulins were determined by ELISA. Bacterial and bifidobacterial communities were determined by 16S rRNA gene sequencing and bifidobacterial groEL sequencing. Results: B. longum subsp. infantis I4MI and I8TI were shown to increase the ration of colonic IgG2a/IgE in male mice (P < 0.05). B6MNI was demonstrated to significantly increase the levels of colonic IFN-γ and IgG2a, as well as the ratio of IgG2a/IgE in female mice (P < 0.05). It was also shown to significantly increase the ratio of colonic IgG2a/IgE (P < 0.05) and reduce the level of colonic IL-4 in male mice (P < 0.05). Furthermore, B6MNI was demonstrated to regulate colonic JAK/STAT pathway in both male and female mice. I4MI, I5TI, and B6MNI were shown to increase the relative abundance of Bifidobacterium and B. longum subsp. infantis in both male and female mice, whereas I8TI was only shown to increase the relative abundance of Bifidobacterium and B. longum subsp. infantis in male mice (P < 0.05). Conclusion: These results indicated supplementation with B. longum subsp. infantis in early infancy may regulate the Th1/Th2 immune balance, which may prevent the development of related diseases.

Metabolomic analysis reveals Ligilactobacillus salivarius CCFM 1266 fermentation improves dairy product quality.

Previous studies have demonstrated that Ligilactobacillus salivarius CCFM 1266 exhibits anti-inflammatory properties and the capability to synthesize niacin. This study aimed to investigate the fermentative abilities of L. salivarius CCFM 1266 in fermented milk. Metabonomic analysis revealed that fermentation by L. salivarius CCFM 1266 altered volatile flavor compounds and metabolite profiles, including heptanal, nonanal, and increased niacin production. Genomic investigations confirmed that L. salivarius CCFM 1266 possess essential genes for the metabolism of fructose and mannose, affirming its proficiency in utilizing fructooligosaccharides and mannan oligosaccharides. The addition of fructooligosaccharides and mannan oligosaccharides during the fermentation process significantly facilitated the proliferation of L. salivarius CCFM 1266 in fermented milk, with growth exceeding 107 colony-forming units (CFU)/mL. This intervention not only augmented the microbial density but also modified the metabolite composition of fermented milk, resulting in an elevated presence of advantageous flavor compounds such as nonanal, 2,3-pentanedione, and 3-methyl-2-butanone. However, its influence on improving the texture of fermented milk was observed to be minimal. Co-fermentation of L. salivarius CCFM 1266 with commercial fermentation starters indicated that L. salivarius CCFM 1266 was compatible, similarly altering metabolite composition and increasing niacin content in fermented milk. In summary, the findings suggest that L. salivarius CCFM 1266 holds substantial promise as an adjunctive fermentation starter, capable of enhancing the nutritional diversity of fermented milk products.

Gut microbiota: a superior operator for dietary phytochemicals to improve atherosclerosis.

Mounting evidence implicates the gut microbiota as a possible key susceptibility factor for atherosclerosis (AS). The employment of dietary phytochemicals that strive to target the gut microbiota has gained scientific support for treating AS. This study conducted a general overview of the links between the gut microbiota and AS, and summarized available evidence that dietary phytochemicals improve AS via manipulating gut microbiota. Then, the microbial metabolism of several dietary phytochemicals was summarized, along with a discussion on the metabolites formed and the biotransformation pathways involving key gut bacteria and enzymes. This study additionally focused on the anti-atherosclerotic potential of representative metabolites from dietary phytochemicals, and investigated their underlying molecular mechanisms. In summary, microbiota-dependent dietary phytochemical therapy is a promising strategy for AS management, and knowledge of "phytochemical-microbiota-biotransformation" may be a breakthrough in the search for novel anti-atherogenic agents.

Comparison of the hepatoprotection of intragastric and intravenous cyanidin-3-glucoside administration: focus on the key metabolites and gut microbiota modulation.

Liver injury is a life-threatening condition, and the hepatoprotective potential of cyanidin-3-glucoside (C3G) has been previously demonstrated. However, due to the low bioavailability, it has been doubtful that relatively low concentrations of intact C3G in vivo could account for these bioactivities. In this study, the hepatoprotective effects of intragastric and intravenous administration of C3G were investigated in a CCl4 induced liver injury model. Intragastric C3G administration was more effective than intravenous C3G injection in reducing serum damage biomarkers, oxidative stress, and inflammatory responses, indicating that absorption of C3G into the bloodstream does not fully account for its observed benefits in vivo. Furthermore, intragastric C3G administration modulated the gut microbiota structure and increased the contents of five metabolites in the feces and serum with high inter-individual variation, indicating the key role of the interaction between C3G and the gut microbiota. At equivalent doses, the metabolites cyanidin and protocatechuic acid exhibited greater efficacy than C3G in reducing apoptosis and ROS production by activating the Nrf2 pathway in an AAPH-induced oxidative stress model. To achieve the desired health effects via C3G-rich food intake, more attention should be paid to microbially derived catabolites. Screening of specific metabolite-producing strains will help overcome individual differences and enhance the health-promoting effects of C3G.

Lactobacillus delbrueckii subsp. bulgaricus Alleviates Acute Injury in Hypoxic Mice.

Acute mountain sickness (AMS) is a common ailment in high-altitude areas caused by the body's inadequate adaptation to low-pressure, low-oxygen environments, leading to organ edema, oxidative stress, and impaired intestinal barrier function. The gastrointestinal tract, being the first to be affected by ischemia and hypoxia, is highly susceptible to injury. This study investigates the role of Lactobacillus delbrueckii subsp. bulgaricus in alleviating acute hypoxic-induced intestinal and tissue damage from the perspective of daily consumed lactic acid bacteria. An acute hypoxia mouse model was established to evaluate tissue injury, oxidative stress, inflammatory responses, and intestinal barrier function in various groups of mice. The results indicate that strain 4L3 significantly mitigated brain and lung edema caused by hypoxia, improved colonic tissue damage, and effectively increased the content of tight junction proteins in the ileum, reducing ileal permeability and alleviating mechanical barrier damage in the intestines due to acute hypoxia. Additionally, 4L3 helped to rebalance the intestinal microbiota. In summary, this study found that Lactobacillus delbrueckii subsp. bulgaricus strain 4L3 could alleviate acute intestinal damage caused by hypoxia, thereby reducing hypoxic stress. This suggests that probiotic lactic acid bacteria that exert beneficial effects in the intestines may alleviate acute injury under hypoxic conditions in mice, offering new insights for the prevention and treatment of AMS.

Biomolecular investigations into BBI reveal an enzymatic mechanism for PUFA isomerisation in bifidobacterium CFA bioconversion strains.

Multiple species of Bifidobacterium exhibit the ability to bioconvert conjugated fatty acids (CFAs), which is considered an important pathway for these strains to promote host health. However, there has been limited progress in understanding the enzymatic mechanism of CFA bioconversion by bifidobacteria, despite the increasing number of studies identifying CFA-producing strains. The protein responsible for polyunsaturated fatty acid (PUFA) isomerization in B. breve CCFM683 has recently been discovered and named BBI, providing a starting point for exploring Bifidobacterium isomerases (BIs). This study presents the sequence classification of membrane-bound isomerases from four common Bifidobacterium species that produce CFA. Heterologous expression, purification, and enzymatic studies of the typical sequences revealed that all possess a single c9, t11 isomer as the product and share common features in terms of enzymatic properties and catalytic kinetics. Using molecular docking and alanine scanning, Lys84, Tyr198, Asn202, and Leu245 located in the binding pocket were identified as critical to the catalytic activity, a finding further confirmed by site-directed mutagenesis-based screening assays. Overall, these findings provide insightful knowledge concerning the molecular mechanisms of BIs. This will open up additional opportunities for the use of bifidobacteria and CFAs in probiotic foods and precision nutrition.