Current Nutrition & Food Science - Online First

Aquaculture advises against using antibiotics and synthetic hormones for tilapia fish growth due to concerns about antimicrobial resistance, environmental contamination, and disruption of the fish microbiome. The search for alternative fish growth promotion strategies has been an extensive one. The effect of yeast (Saccharomyces cerevisiae) on intestinal histology, biochemical parameters, and haematology indices of Oreochromis niloticus is examined in this study.

To produce the experimental diet of 35% crude protein, yeast at varying quantities were added to the basal feed ingredient in the following amounts: 0, 5, 10 and 15 g/kg, which corresponded to the groups G1 (control), G2, G3, and G4, respectively. Twelve (12) concrete ponds, each with a capacity of 1,500 litres, were the culture structures for the experiment. Two hundred and forty mixed-sex Oreochromis niloticus fingerlings were stocked, and each pond was randomly allocated twenty fingerlings. Each parameter assessed was replicated 3 times.

The result on growth parameters showed that the highest final mean weight (86.33± 3.51 g), average daily growth (1.14±0.05 g), percentage mean weight gain (278.05±4.59%), and Specific Growth rate (7.41±0.08 g) were obtained in G3 fed with 10g/kg of Saccharomyces cerevisiae. While the lowest final weight (38.00±4.58 g), average daily growth (0.28±0.07 g), percentage mean weight gain (68.23±16.66%), Specific Growth rate (4.84±0.50 g) was obtained in G1, fish fed with control diet. The study's results on blood parameters indicate that the O. niloticus fed 5 g/kg of yeast in G2 had the highest mean values of Red Blood Cells at 4.49±0.23 × 10⁶ µ/l, Haemoglobin at 3.73±0.20 g/dl, and Mean Cell Haemoglobin Content at 46.03±0.07. While the fish fed 15 g/kg of yeast in G4 had the lowest mean values of 3.48±0.35 × 10⁶ µ/l, 3.73±0.31 g/dl, and 31.80±0.05, respectively. The greatest mean values of White Blood Cells at 10.53±0.35 × 10³ µ/l, Parked Cell Volume at 15.50±0.50%, and Mean (red) Cell Volume at 38.08±0.06 were observed in fish fed with the control diet. Fish given 5 g/kg (G2) had the greatest levels of total protein, glucose, globulin, and cholesterol, with mean values of 62.00±0.93 g/dl, 14.30±0.20 g/dl, 48.00±1.00 and 3.34±0.05 g/dl respectively.

The study suggests that increasing yeast concentration in O. niloticus diets increases mucosa surface area and promotes nutrient absorption, with minimal adverse effects on intestinal histology, biochemical parameters, and haematology indices of Oreochromis niloticus.

Guanidinoacetic acid (GAA) serves as a primary methyl group acceptor, with its conversion to creatine constituting a major methylation pathway. While prior studies have established a relationship between dietary GAA intake and total folate levels, its effects on individual folate vitamers remain poorly understood. The main objective of this study was to investigate the association between dietary GAA intake and serum concentrations of total folate and specific folate vitamers in a nationally representative U.S. population.

Data were drawn from the 2011–2012 National Health and Nutrition Examination Survey (NHANES), including 8,485 participants. Dietary GAA intake was estimated using 24-hour dietary recall, and serum concentrations of total folate and five folate vitamers were measured through standardized laboratory analyses. Multivariable linear regression models, adjusted for demographic and dietary covariates, were used to assess associations.

Higher dietary GAA intake was significantly associated with lower serum levels of total folate (B = −0.280, P < 0.001), 5-methyltetrahydrofolate (5-methyl-THF; B = −0.265, P < 0.001), 5,10-methenyltetrahydrofolate (5,10-methenyl-THF; B = −0.001, P = 0.021), and 4-α-hydroxy-5-methyl-THF (MeFox; B = −0.007, P = 0.006). These associations persisted after adjustment for potential confounders.

5-methyl-THF and 5,10-methenyl-THF appear to be more sensitive biomarkers of dietary GAA exposure compared to other folate vitamers, such as folic acid and tetrahydrofolate; these compounds should be routinely evaluated to effectively monitor the nutritional effects of GAA in human studies.

Dietary intake of GAA is inversely associated with serum concentrations of total folate and key folate vitamers. These findings suggest that GAA may influence methyl group availability and homocysteine remethylation via its impact on folate metabolism. Further investigation is warranted to explore the metabolic and clinical implications of these associations.

Diabetes mellitus is a significant public health concern as its global prevalence continues to rise. Non-pharmacological treatments may offer promising results for diabetic patients. This study aimed to evaluate the effects of cinnamon-based cookies on blood glucose and antioxidant levels in diabetic rats.

A randomized block design was used, involving five groups: a non-diabetic group, a positive control group receiving 0.6 mg/kg/day of glibenclamide, a negative control group receiving aqua dest, a group receiving cinnamon extract cookies (0.2 g/kg), and a group receiving powdered cinnamon cookies (0.6 g/kg). A total of 40 Sprague-Dawley rats were randomly divided into these groups (n = 8 per group). Diabetes was induced using streptozotocin (50 mg/kg). The intervention lasted for 21 days, during which body weight and blood glucose levels were monitored on days 0, 3, 7, 14, and 21. At the end of the intervention, the rats were sacrificed, and blood serum was collected via intracardiac puncture. Body weight was measured using a digital scale, while blood glucose levels were determined using a glucometer. The serum was then analyzed for SOD, MDA, and insulin levels using the ELISA method.

The study demonstrated that both types of cinnamon cookies significantly decreased blood glucose levels by day 3, with the cinnamon powder cookies achieving levels comparable to those of non-diabetic rats by day 7. Additionally, both types of cookies significantly improved SOD and insulin levels and reduced MDA levels in the rats. However, the body weight of the diabetic rats was not fully restored.

These findings suggest that cinnamon could be utilized in food product development for blood glucose control, with cinnamon powder potentially offering more favorable results.