Effect of Lacticaseibacillus paracasei K56 with galactooligosaccharide synbiotics on obese individuals: an in vitro fermentation model.

BACKGROUND: The use of synbiotics is emerging as a promising intervention strategy for regulating the gut microbiota and for preventing or reducing obesity, in comparison with the use of probiotics or prebiotics alone. A previous in vivo study revealed that Lacticaseibacillus paracasei K56 (L. paracasei K56) could alleviate obesity induced in high-fat-diet mice; however, the effect of the synbiotic combination of L. paracasei K56 and prebiotics in obese individuals has not been explored fully. RESULTS: The effect of prebiotics on the proliferation of L. paracasei K56 was determined by spectrophotometry. The results showed that polydextrose (PG), xylooligosaccharide (XOS), and galactooligosaccharide (GOS) had a greater potential to be used as substrates for L. paracasei K56 than three other prebiotics (melitose, stachyose, and mannan-oligosaccharide). An in vitro fermentation model based on the feces of ten obese female volunteers was then established. The results revealed that K56_GOS showed a significant increase in GOS degradation rate and short-chain fatty acid (SCFA) content, and a decrease in gas levels, compared with PG, XOS, GOS, K56_PG, and K56_XOS. Changes in these microbial biomarkers, including a significant increase in Bacteroidota, Bifidobacterium, Lactobacillus, Faecalibacterium, and Blautia and a decrease in the Firmicutes/Bacteroidota ratio and Escherichia-Shigella in the K56_GOS group, were associated with increased SCFA content and decreased gas levels. CONCLUSION: This study demonstrates the effect of the synbiotic combination of L. paracasei K56 and GOS on obese individuals and indicates its potential therapeutic role in obesity treatment. © 2024 Society of Chemical Industry.

Efficacy of Bifidobacterium animalis subsp. lactis BL-99 in the treatment of functional dyspepsia: a randomized placebo-controlled clinical trial.

Current treatment for functional dyspepsia (FD) has limited and unsustainable efficacy. Probiotics have the sustainable potential to alleviate FD. This randomized controlled clinical trial (Chinese Clinical Trial Registry, ChiCTR2000041430) assigned 200 FD patients to receive placebo, positive-drug (rabeprazole), or Bifidobacterium animalis subsp. lactis BL-99 (BL-99; low, high doses) for 8-week. The primary outcome was the clinical response rate (CRR) of FD score after 8-week treatment. The secondary outcomes were CRR of FD score at other periods, and PDS, EPS, serum indicators, fecal microbiota and metabolites. The CRR in FD score for the BL-99_high group [45 (90.0%)] was significantly higher than that for placebo [29 (58.0%), p = 0.001], BL-99_low [37 (74.0%), p = 0.044] and positive_control [35 (70.0%), p = 0.017] groups after 8-week treatment. This effect was sustained until 2-week after treatment but disappeared 8-week after treatment. Further metagenomic and metabolomics revealed that BL-99 promoted the accumulation of SCFA-producing microbiota and the increase of SCFA levels in stool and serum, which may account for the increase of serum gastrin level. This study supports the potential use of BL-99 for the treatment of FD.

Heat-Killed Bifidobacterium longum BBMN68 in Pasteurized Yogurt Alleviates Mugwort Pollen-Induced Allergic Airway Responses through Gut Microbiota Modulation in a Murine Model.

Many probiotic bacteria have been proven to prevent allergic airway responses through immunomodulation. This study was conducted to evaluate the effects of heat-killed Bifidobacterium longum BBMN68 (BBMN68) in pasteurized yogurt on the alleviation of mugwort pollen (MP)-induced allergic inflammation. BALB/c mice aged 5-6 weeks were randomly assigned and fed pasteurized yogurt containing heat-killed BBMN68 for 27 days, followed by allergic sensitization and challenge with MP extract. The allergic mice that received pasteurized yogurt containing heat-killed BBMN68 had improved immune status, including a lower serum IgE level, decreased serum interleukin (IL)-4, IL-5, and IL-13 concentrations, and alleviated airway inflammation manifested by increased macrophage and decreased eosinophil and neutrophil counts in BALF, as well as airway remodeling and suppressed peribronchial cellular infiltration. Moreover, oral administration of pasteurized yogurt containing heat-killed BBMN68 significantly modulated gut microbiota composition by influencing the proportion of beneficial genera associated with inflammation and immunity, such as Lactobacillus, Candidatus_Saccharimonas, Odoribacter, and Parabacteroides, which also negatively correlated with serum IgE and Th2 cytokine levels. These results demonstrated that pasteurized yogurt containing heat-killed BBMN68 had mitigative effects on allergic airway inflammation, likely through maintaining the systemic Th1/Th2 immune balance by altering the structure and function of the gut microbiota.

Bifidobacterium animalis subsp. lactis MN-Gup protects mice against gut microbiota-related obesity and endotoxemia induced by a high fat diet.

Obesity has become a public health concern due to its global prevalence and high risk of complications such as endotoxemia. Given the important role of gut microbiota in obesity, probiotics targeting gut microbiota have been developed and applied to alleviate obesity. However, most studies focused on the effects of probiotics on pre-existing obesity, and the preventive effects of probiotics against obesity were rarely studied. This study aimed to investigate the preventive effects of Bifidobacterium animalis subsp. lactis MN-Gup (MN-Gup) and fermented milk containing MN-Gup against high fat diet (HFD)-induced obesity and endotoxemia in C57BL/6J mice. The results showed that MN-Gup, especially the high dose of MN-Gup (1 × 1010CFU/kg b.w.), could significantly protect mice against HFD-induced body weight gain, increased fat percentage, dyslipidemia, and increased lipopolysaccharides (LPS). Fermented milk containing MN-Gup had better preventive effects on fat percentage and dyslipidemia than fermented milk without MN-Gup, but its overall performance was less effective than MN-Gup. Furthermore, MN-Gup and fermented milk containing MN-Gup could alter HFD-affected gut microbiota and regulate obesity- or endotoxemia-correlated bacteria, which may contribute to the prevention of obesity and endotoxemia. This study revealed that MN-Gup could reduce obesity and endotoxemia under HFD, thereby providing a potential application of MN-Gup in preventing obesity.

3-Alkyl-2-pyridyl Directing Group-Enabled C2 Selective C-H Silylation of Indoles and Pyrroles via an Iridium Catalyst.

An iridium-catalyzed, directing group-enabled site selective intra- and intermolecular silylation of indoles and pyrroles with hydrosilanes has been developed under ligand-free conditions. Fine-tuning of the removable 3-alkyl-2-pyridyl directing group was found to be crucial for achieving high yields for C2-silylated indole and pyrrole products. Moreover, the scalability was demonstrated, and further transformations of the silylation products were achieved.

A Wideband Cryogenic Readout Amplifier with Temperature-Insensitive Gain for SNSPD.

This paper presents a temperature-insensitive wideband cryogenic amplifier for superconducting nanowire single-photon detectors (SNSPD). With a proposed folded diode-connected transistor load to realize a good device-tracking feature, the theoretical derivations the simulations and test results prove that the amplifier-gain cell has a stable gain performance over a wide temperature range, solving the issues of a lack of the accurate cryogenic device models. The amplifier achieves a gain of 26 dB from 100 kHz to 1 GHz at 4.2 K, consuming only 1.8 mW from a 1.8 V supply. With a 0.13-µm SiGe BiCMOS process, the chip area is 0.5 mm².