Dietary Egg Protein Prevents Hyperhomocysteinemia via Upregulation of Hepatic Betaine-Homocysteine S-Methyltransferase Activity in Folate-Restricted Rats

Understanding metabolic phenomena accompanying high levels of yeast in broiler chicken diets and resulting carcass weight and meat quality changes

The use of yeast as a protein source was investigated in broiler chicken diets on carcass quality, storage stability, and metabolite changes in leg meat. Male Ross 308 chickens (n = 100) were fed with one of 5 diets: control, control added 0.6% formic acid, or 3 diets where soybean meal was substituted with 10, 20, and 30% crude protein from inactivated yeast Cyberlindnera jadinii (CJ10, CJ20, CJ30, respectively). The yeast-containing diets reduced carcass weight, linoleic acid, and warm-over flavor in chicken leg meat. Protein degradation-related metabolite biomarkers were upregulated in the leg of chickens that were fed yeast-containing diets, indicating an adaptive response to the loss of appetite. Chill-stored leg meat of birds fed yeast diets showed increased browning and metallic taste compared with those fed the control diet. The use of formic acid in the diet reduced cooking loss and had a positive effect on vitamin B content.

Letrozole-Induced Polycystic Ovary Syndrome Attenuates Cystathionine-β Synthase mRNA and Protein Abundance in the Ovaries of Female Sprague Dawley Rats

BACKGROUND

Polycystic ovary syndrome (PCOS) is an endocrine disorder that affects 10% of reproductive-aged women and leads to hyperandrogenism, anovulation, and infertility. PCOS has been associated with elevated serum homocysteine as well as altered methylation status; however, characterization of one-carbon metabolism (OCM) in PCOS remains incomplete.

OBJECTIVES

The aim of our research was to assess OCM in a letrozole-induced Sprague Dawley rat model of PCOS.

METHODS

Five-week-old female rats (n = 36) were randomly assigned to letrozole [0.9 mg/kg body weight (BW)] treatment or vehicle (carboxymethylcellulose) control that was administered via subcutaneously implanted slow-release pellets every 30 d. For both treatment groups, 12 rats were randomly assigned to be euthanized during proestrus at one of the following time points: 8, 16, or 24 wk of age. Daily BW was measured and estrous cyclicity was monitored during the last 30 d of the experimental period. Ovaries were collected to assess mRNA and protein abundance of OCM enzymes.

RESULTS

Letrozole-induced rats exhibited 1.9-fold higher cumulative BW gain compared with control rats across all age groups (P < 0.0001). Letrozole reduced the time spent at proestrus (P = 0.0001) and increased time in metestrus (P < 0.0001) of the estrous cycle. Cystathionine β-synthase (Cbs) mRNA abundance was reduced in the letrozole-induced rats at 16 (59%; P < 0.05) and 24 (77%; P < 0.01) wk of age. In addition, CBS protein abundance was 32% lower in 8-wk-old letrozole-induced rats (P = 0.02). Interestingly, betaine-homocysteine S-methyltransferase mRNA abundance increased as a function of age in letrozole-induced rats (P = 0.03).

CONCLUSION

These data demonstrate that letrozole-induced PCOS Sprague Dawley rats temporally decrease the ovarian abundance of Cbs mRNA and protein in the early stages of PCOS.

Screening of folate-producing lactic acid bacteria and modulatory effects of folate-biofortified yogurt on gut dysbacteriosis of folate-deficient rats

Folate deficiency is accompanied by gut dysbacteriosis. To understand dietary intervention in folate deficiency, a folate-deficient rat model was used to evaluate the modulatory effects of folate-producing lactic acid bacteria (LAB) and biofortified yogurt on gut dysbacteriosis. The high folate-producing strain was screened from 12 LABs, and its variant, namely Lactobacillus plantarum GSLP-7 V, with folate productivity in yogurt at 3.72 μg mL-1, was obtained by stressing with 5.0 mg L-1 methotrexate and 100.00 mg L-1 Ca2+. To our knowledge, this is the highest folate productivity in yogurt by LAB strains ever reported. To further examine the folate supplement effect in vivo, a folate-deficient rat model was established and fed a folate-free diet for 8 weeks. Also, the effects of L. plantrum GSLP-7 V, yogurt fermented with L. plantrum GSLP-7 V, plain yogurt, and chemical folic acid on folate deficiency and gut dysbacteriosis were examined. Analysis of the change in gut microbiota showed that the gut dysbacteriosis was significantly correlated with folate deficiency. Administration of L. plantrum GSLP-7 V and its fermented yogurt for 10 days restored the disrupted gut microbiota and recovered the serum folate and homocysteine to normal levels, while chemical folic acid worsened the gut dysbacteriosis. Chemical folic acid only enriched Akkermansia, while L. plantrum GSLP-7 V and its fermented yogurt modulated the gut microbiota comprehensively through 7 and 10 key genera, respectively. This study confirmed the effectiveness of dietary intervention with folate-biofortified yogurt through modulating gut microbiota, suggesting the potential of the folate-producing LAB as an agent for the treatment of folate-deficiency related diseases.