Role of Bifidobacterium spp. intake in improving depressive mood and well-being and its link to kynurenine blood level: an interventional study

OBJECTIVES

Evidence for the contribution of the brain-gut-microbiota axis to the depression pathophysiology is increasing nowadays. Disturbed gut microbiota equilibrium along with bad dietary habits both lead to kynurenine pathway abnormalities contributing to the depression pathophysiology. In this respect, many studies are found but the interventional clinical trials are limited. The present interventional study aims to evaluate the impact of Bifidobacterium spp. supplementation together with improving dietary intake on depressive mood and well-being and their correlation with kynurenine blood level in adult Egyptian healthy volunteers.

METHODS

A number of 98 healthy female volunteers with a mean age of 46.96 ± 1.82 years were selected and enrolled in this study. They were given yogurt enriched with Bifidobacterium spp. daily for eight weeks. Clinical examination as well as questionnaires for the evaluation of psychological well-being and depression were done at base line and after eight weeks of intervention. Fasting blood samples and stool samples were collected from all subjects at baseline and eight weeks after the intervention for the investigation of serum kynurenine concentration, blood hemoglobin, serum transaminases (ALT & AST) serum urea and creatinine as well as fecal Bifidobacterium count.

RESULTS

Data revealed that both depression and well-being showed highly significant improvement combined with significant drop in kynurenine blood level after intervention. Also, a significant rise in fecal Bifidobacterium count and a significant improvement in hemoglobin level and activity of liver enzymes were recorded. After intervention, a significant negative correlation was recorded between depression and fecal Bifidobacterium count as well as between serum kynurenine level, and well-being.

CONCLUSION

Bifidobacterium spp. supplementation combined with improvement in dietary intake resulted in improvement of depressive mood and well-being and reduced kynurenine blood level.

Biochemical characterization and insights into the potency of the acidic Aspergillus niger NRC114 purified α-galactosidase in removing raffinose family oligosaccharides from soymilk yogurt

BACKGROUND

Because humans lack α-galactosidase, foods containing certain oligosaccharides from the raffinose family, such as soybeans and other legumes, may disrupt digestion and cause flatulence.

RESULTS

Aspergillus niger NRC114 α-galactosidase was purified using protein precipitation, gel filtration, and ion exchange chromatography steps, which resulted in a 123-fold purification. The purified enzyme was found to be 64 kDa using the SDS-PAGE approach. The optimum pH and temperature of the purified α-galactosidase were detected at pH 3.5 and 60 ºC, respectively. The pure enzyme exhibited potent acidic pH stability at pH 3.0 and pH 4.0 for 2 h, and it retained its full activity at 50 ºC and 60 ºC for 120 min and 90 min, respectively. The enzyme was activated using 2.5 mM of K⁺, Mg²⁺, Co²⁺, or Zn²⁺ by 14%, 23%, 28%, and 11%, respectively. The K_m and V_max values of the purified enzyme were calculated to be 0.401 µM and 14.65 μmol min^-1, respectively. The soymilk yogurt showed an increase in its total phenolic content and total flavonoids after enzyme treatment, as well as several volatile compounds that were detected and identified using GC-MS analysis. HPLC analysis clarified the enzymatic action in the hydrolysis of raffinose family oligosaccharides.

CONCLUSION

The findings of this study indicate the importance of A. niger NRC114 α-galactosidase enzyme for future studies, especially its applications in a variety of biological fields.

A statistical strategy for optimizing the production of α-galactosidase by a newly isolated Aspergillus niger NRC114 and assessing its efficacy in improving soymilk properties

Background

α-Galactosidase is widely distributed in plants, microorganisms, and animals, and it is produced by different fungal sources. Many studies have confirmed the valuable applications of α-galactosidase enzymes for various biotechnological purposes, like the processing of soymilk.

Results

Aspergillus niger NRC114 was exploited to produce the extracellular α-galactosidase. One factor per time (OFT) and central composite design (CCD) approaches were applied to determine the optimum parameters and enhance the enzyme production. The CCD model choices of pH 4.73, 1.25% mannose, 0.959% meat extract, and 6-day incubation period have succeeded in obtaining 25.22 U/mL of enzyme compared to the 6.4 U/mL produced using OFT studies. Treatment of soymilk by α-galactosidase caused an increase in total phenols and flavonoids by 27.3% and 19.9%, respectively. Antioxidant measurements revealed a significant increase in the enzyme-treated soymilk. Through HPLC analysis, the appearance of sucrose, fructose, and glucose in the enzyme-treated soymilk was detected due to the degradation of stachyose and raffinose. The main volatile compounds in raw soymilk were acids (45.04%) and aldehydes (34.25%), which showed a remarkable decrease of 7.82% and 20.03% after treatment by α-galactosidase.

Conclusions

To increase α-galactosidase production, the OFT and CCD approaches were used, and CCD was found to be four times more effective than OFT. The produced enzyme proved potent enough to improve the properties of soymilk, avoiding flatulence and undesirable tastes and odors.

Graphical Abstract

Bifidobacterium longum Suppresses Murine Colorectal Cancer through the Modulation of oncomiRs and Tumor Suppressor miRNAs

The modulatory role of the Bifidobacterium longum (BL), isolated from women breast milk, on some oncogenic and tumor suppressor miRNAs as well as IL-1β and IL6 targeted-miRNAs was investigated using murine colorectal cancer (CRC) induced on the top of inflammatory ulcerative colitis model. The investigation of the oncomiRs miR-21a and miR-155, which regulate IL-6 and IL-1β expression, indicated that both was depressed by BL-administration in healthy and in CRC-mice. BL-administration induced the tumor suppressor miRNAs (miR-145 and miR-15a) expression in both of the healthy and in CRC-mice. The miR-146a expression, which regulates both of IL-1β and IL-6 expression, was decreased after the BL-administration in both of the healthy and in CRC-mice. In CRC-mice, NF-Kb concentration was elevated, however this NF-Kb induction was diminished after the treatment with BL. BL highly enhanced the IL-1β and IL-6 mRNA and protein concentrations in healthy mice. The administration of BL to CRC-mice resulted in a dramatic increase in IL-1β mRNA and IL-1β concentration, which in contrast was accompanied with a decrease in the IL-6 mRNA and IL-6 concentration. BL-administration resulted in a drop in the aberrant crypt foci number in CRC-mice and increased necrosis and fibrosis of the colon cells. The modulatory influence of B. longum on microRNAs may provide an important therapeutic impact in CRC through inhibition of the proliferation, invasion, apoptosis, and cell cycle of tumor cells.

The role of probiotics in children with autism spectrum disorder: A prospective, open-label study

OBJECTIVE

There are limited data on the efficacy of probiotics in children with ASD, therefore, this study aims to evaluate the efficacy and tolerability of probiotics in an Egyptian cohort of children with ASD.

METHODS

Gastrointestinal (GI) flora were assessed by quantitative real-time PCR of stool samples of 30 autistic children from 5 to 9 years old. GI symptoms of autistic children were assessed with a modified six-item Gastrointestinal Severity Index (6-GSI) questionnaire, and autistic symptoms were assessed with Autism Treatment Evaluation Checklist (ATEC) before and after 3 months of supplementation of probiotics nutritional supplement formula (each gram contains 100 × 10⁶ colony forming units of three probiotic strains; Lactobacillus acidophilus, Lactobacillus rhamnosus and Bifidobacteria longum).

RESULTS

After probiotic supplementation, the stool PCR of autistic children showed increases in the colony counts of Bifidobacteria and Lactobacilli levels, with a significant reduction in their body weight as well as significant improvements in the severity of autism (assessed by the ATEC), and gastrointestinal symptoms (assessed by the 6-GSI) compared to the baseline evaluated at the start of the study.

CONCLUSIONS

We concluded that probiotics have beneficial effects on both behavioral and GI manifestations of ASD. Probiotics (a non-pharmacological and relatively risk-free option) could be recommended for children with ASD as an adjuvant therapy. At this stage, this study is a single center with a small number of patients and a great deal of additional wide-scale randomized controlled trials are needed to critically confirm the efficacy of probiotics in ASD.

TRIAL REGISTRATION NUMBER

UMIN-CTR Study Design: Trial Number UMIN000026157.