Pablo Christiano Barboza Lollo

Probiotic yogurts manufactured with increased glucose oxidase levels: Postacidification, proteolytic patterns, survival of probiotic microorganisms, production of organic acid and aroma compounds

We investigated the effect of increased glucose oxidase concentration as a technological option to decrease oxidative stress during the processing of probiotic yogurts. Probiotic yogurts were produced with increased concentrations of glucose oxidase (0, 250, 500, 750, or 1,000 mg/kg) and submitted to physicochemical and microbiological analysis at 1, 15, and 30 d of refrigerated storage. Higher concentrations of glucose oxidase (750 and 1,000 mg/kg) and a longer storage time were found to have an influence on the characteristics of the probiotic yogurt, contributing to more extensive postacidification, an increase in the dissolved oxygen level, and higher proteolysis. In addition, increased production of aroma compounds (diacetyl and acetaldehyde) and organic acids (mainly lactic acid) and a decrease in the probiotic bacteria count were reported. The use of glucose oxidase was a feasible option to minimize oxidative stress in probiotic yogurts. However, supplementation with excessive amounts of the enzyme may be ineffective, because insufficient substrate (glucose) is present for its action. Consumer tests should be performed to evaluate changes in the sensory attributes of the probiotic yogurts with increased supplementation of glucose oxidase. In addition, packaging systems with different permeability to oxygen should be evaluated.

Effect of the inoculation level of Lactobacillus acidophilus in probiotic cheese on the physicochemical features and sensory performance compared with commercial cheeses.

The complex metabolism of probiotic bacteria requires several technological options to guarantee the functionally of probiotic dairy foods during the shelf life. This research aimed to evaluate the effect of the supplementation of increasing amounts of Lactobacillus acidophilus (0, 0.4, or 0.8 g/L of milk) on the physicochemical parameters and sensory acceptance of Minas fresh cheese. In addition, the sensory acceptance of probiotic cheeses was assessed using a consumer test and compared with commercial cheeses (conventional and probiotic). High counts (9.11 to 9.42 log cfu/g) of L. acidophilus were observed throughout the shelf life, which contributed to the maintenance of its probiotic status and resulted in lower pH values and greater production of organic acids. The probiotic cheeses presented lower scores for appearance, aroma, and texture compared with conventional cheeses. Internal preference mapping explained almost 60% of the total variation of the data and showed a large number of consumers concentrated near the conventional cheeses, demonstrating greater preference for these samples. The findings indicated that some negative sensory effects could occur when high level of supplementation with L. acidophilus is used in probiotic cheese processing.

Hypertension parameters are attenuated by the continuous consumption of probiotic Minas cheese

The aim of this study was to investigate the effects of ingestion of probiotic Minas Frescal cheese (PMFC) on hypertension parameters in spontaneously hypertensive rats (SHRs). Twenty-eight animals were divided into four groups fed with different experimental diets: control initial (CI), control final (CF), traditional Minas Frescal cheese (CMFC), and PMFC. The latter two groups were fed with 20g of cheese per day for 15days. All groups were assessed for blood pressure and health parameters. The results show that the group fed with PMFC exhibited significantly lower blood pressure when compared to the group fed with CMFC, CI, and CF. Regarding the other health parameters, an improvement in blood lipids (triglycerides and cholesterol) was observed for the group fed with PMFC as compared with CMFC. No significant differences were observed in renal function parameters. Our findings suggest that consumption of probiotic cheese can be potentially useful to improve the cardiovascular health parameters.

Probiotic cheese attenuates exercise-induced immune suppression in Wistar rats.

Intense physical activity results in a substantial volume of stress and hence a significant probability of immunosuppression in athletes, with milk proteins being, perhaps, the most recommended protein supplements. Consumption of a probiotic cheese can attenuate immune suppression induced by exhausting exercise in rats. A popular Brazilian fresh cheese (Minas Frescal cheese) containing Lactobacillus acidophilus LA14 and Bifidobacterium longum BL05 was fed for 2wk to adult Wistar rats, which then were brought to exhaustion on the treadmill. Two hours after exhaustion, the rats were killed and material was collected for the determination of serum uric acid, total and high-density lipoprotein cholesterol fraction, total protein, triacylglycerols, aspartate aminotransferase, alanine aminotransferase, creatine kinase, and blood cell (monocyte, lymphocyte, neutrophil, and leukocyte) counts. Exercise was efficient in reducing lymphocyte counts, irrespective of the type of ingested cheese, but the decrease in the group fed the probiotic cheese was 22% compared with 48% in the animals fed regular cheese. Monocyte counts were unaltered in the rats fed probiotic cheese compared with a significant decrease in the rats fed the regular cheese. Most importantly, ingestion of the probiotic cheese resulted in a >100% increase in serum high-density lipoprotein cholesterol and a 50% decrease in triacylglycerols. We conclude that probiotic Minas Frescal cheese may be a viable alternative to enhance the immune system and could be used to prevent infections, particularly those related to the physical overexertion of athletes.

Taurine supplementation improves liver glucose control in normal protein and malnourished mice fed a high-fat diet

SCOPE Poor nutrition during the perinatal period is associated with an increased risk for metabolic syndrome in adulthood. Taurine (TAU) regulates β-cell function and glucose homeo-stasis. Here, we assessed the effects of TAU supplementation upon adiposity and glucose control in malnourished mice fed a high-fat diet (HFD). METHODS AND RESULTS Weaned male C57BL/6J mice were fed a control (14% protein - C) or a protein-restricted (6% protein - R) diet for 6 weeks. Afterwards, mice received or not an HFD for 8 weeks (CH and RH). Half of the HFDmice were supplemented with 5% TAU after weaning (CHT and RHT). Protein restriction led to typical malnutrition features. HFD increased body weight, adiposity, and led to hyperleptinemia, hyperphagia, glucose intolerance, and higher liver glucose output in RH and CH groups. Fasted R mice showed higher plasma adiponectin levels and increased phosphorylation of the AMP-activated protein kinase (p-AMPK) in the liver. These parameters were reduced in RH mice and increased p-AMPK persisted in RHT. TAU prevented obesity and improved glucose tolerance only in CHT, but liver glucose control was ameliorated in both supplemented groups. Better CHT liver glucose control was linked to increased Akt (thymoma viral proto-oncogene/protein kinase B) phosphorylation. CONCLUSION Malnourished mice fed an HFD developed obesity, glucose intolerance, and increased liver glucose output. TAU preserved only normal liver glucose control in RHT mice, an effect associated with increased liver p-AMPK content.

A dipeptide and an amino acid present in whey protein hydrolysate increase translocation of GLUT-4 to the plasma membrane in Wistar rats.

Whey protein hydrolysate (WPH) is capable of increasing muscle glycogen reserves and of concentrating the glucose transporter in the plasma membrane (PM). The objective of this study was to determine which WPH components could modulate translocation of the glucose transporter GLUT-4 to the PM of animal skeletal muscle. Forty-nine animals were divided into 7 groups (n=7) and received by oral gavage 30% glucose plus 0.55 g/kg body mass of the following WPH components: (a) control; (b) WPH; (c) L-isoleucine; (d) L-leucine; (e) L-leucine plus L-isoleucine; (f) L-isoleucyl-L-leucine dipeptide; (g) L-leucyl-L-isoleucine dipeptide. After receiving these solutions, the animals were sacrificed and the GLUT-4 analysed by western blot. Additionally, glycogen, glycaemia, insulin and free amino acids were also determined by standard methods. Of the WPH components tested, the amino acid L-isoleucine and the peptide L-leucyl-L-isoleucine showed greater efficiency in translocating GLUT-4 to the PM and of increasing glucose capture by skeletal muscle.

Whey protein hydrolysate enhances the exercise-induced heat shock protein (HSP70) response in rats.

Whey protein has been suggested to be potential protective agent against various forms of stress. The heat shock protein HSP70 confers greater cellular tolerance against stressors. The present study evaluated the effects of whey protein intake on HSP70 expression. Forty-eight male Wistar rats were divided into sedentary and exercised groups, and each group was fed as a protein source casein (CAS), whey protein (WP) or whey protein hydrolysate (WPH) for 3weeks. Exercise on a treadmill was used as the source of stress in the animals from the exercised group. The results showed a larger increase in HSP70 expression in the soleus, gastrocnemius and lung of the WPH-fed rats than WP or casein-fed rats. HSP70 expression in the sedentary rats was very low, independent of the diet or tissue. Protein carbonyls were lower in the group that consumed WPH. These data suggest that the consumption of WPH enhances HSP70 expression.

Whey protein hydrolysate increases translocation of GLUT-4 to the plasma membrane independent of insulin in wistar rats.

Whey protein (WP) and whey protein hydrolysate (WPH) have the recognized capacity to increase glycogen stores. The objective of this study was to verify if consuming WP and WPH could also increase the concentration of the glucose transporters GLUT-1 and GLUT-4 in the plasma membrane (PM) of the muscle cells of sedentary and exercised animals. Forty-eight Wistar rats were divided into 6 groups (n = 8 per group), were treated and fed with experimental diets for 9 days as follows: a) control casein (CAS); b) WP; c) WPH; d) CAS exercised; e) WP exercised; and f) WPH exercised. After the experimental period, the animals were sacrificed, muscle GLUT-1 and GLUT-4, p85, Akt and phosphorylated Akt were analyzed by western blotting, and the glycogen, blood amino acids, insulin levels and biochemical health indicators were analyzed using standard methods. Consumption of WPH significantly increased the concentrations of GLUT-4 in the PM and glycogen, whereas the GLUT-1 and insulin levels and the health indicators showed no alterations. The physical exercise associated with consumption of WPH had favorable effects on glucose transport into muscle. These results should encourage new studies dealing with the potential of both WP and WPH for the treatment or prevention of type II diabetes, a disease in which there is reduced translocation of GLUT-4 to the plasma membrane.

Chia (Salvia hispanica L.) enhances HSP, PGC-1α expressions and improves glucose tolerance in diet-induced obese rats

OBJECTIVE The aim of this study was to investigate the effects of chia seed and chia oil on heat shock protein (HSP) and related parameters in diet-induced obese rats. METHODS Animals were divided in six groups: control, high-fat and high-fructose diet (HFF), and HFF with chia seed or chia oil in short (6-wk) and long (12-wk) treatments. Plasma indicators of glucose tolerance and liver damage, skeletal muscle expression of antioxidant enzymes, and proteins controlling oxidative energy metabolism were determined. The limit of significance was set at P < 0.05. RESULTS The HFF diet induced glucose intolerance, insulin resistance, oxidative stress, and altered parameters related to obesity complications. The consumption of chia seed or chia oil did not reduce body weight gain or abdominal fat accumulation. However, chia seed and chia oil in both treatments improved glucose and insulin tolerance. Chia oil in both treatments induced expression of HSP70 and HSP25 in skeletal muscle. Short treatment with chia seed increased expression of HSP70, but not HSP25. Chia oil in both treatments restored superoxide dismutase and glutathione peroxidase expression. Extended treatment with chia seed and short treatment with chia oil restored peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) expression. CONCLUSION Chia oil restored the antioxidant system and induced the expression of a higher number of proteins than chia seed. The present study demonstrated new properties and molecular mechanisms associated with the beneficial effects of chia seed and chia oil consumption in diet-induced obese rats.

Assessment of antioxidant activity, lipid profile, general biochemical and immune system responses of Wistar rats fed with dairy dessert containing Lactobacillus acidophilus La-5

The viability and survival of Lactobacillus acidophilus La5 under in vitro simulated gastrointestinal in probiotic dairy dessert was assessed. In addition, the effects of regular consumption of the dessert (5g/day) on the lipid profile, immune system, and antioxidant/biochemical status of Wistar rats were also evaluated after 2weeks of treatment. Adequate counts of L. acidophilus La-5 were observed regards the viability and gastrointestinal conditions. The probiotic dairy dessert was efficient in reducing the LDL-cholesterol, triacylglycerol and increased the HDL-cholesterol in serum. Aspartate amino transferase, alanine aminotransferase, total protein, albumin, heat shock proteins, immune system responses, and blood-cells counts (monocyte, lymphocyte, neutrophil and leucocyte) were not affected (p>0.05) after 15days of treatment. Overall, the probiotic dairy dessert may be a viable alternative to enhance the blood lipid profile and could be used to improve the antioxidant defenses.