Gordon A. Zello

Low-dose creatine combined with protein during resistance training in older men.

PURPOSE To determine whether low-dose creatine and protein supplementation during resistance training (RT; 3 d x wk(-1); 10 wk) in older men (59-77 yr) is effective for improving strength and muscle mass without producing potentially cytotoxic metabolites (formaldehyde). METHODS Older men were randomized (double-blind) to receive 0.1 g x kg(-1) creatine + 0.3 g x kg(-1) protein (CP; n = 10), creatine (C; n = 13), or placebo (PLA; n = 12) on training days. Measurements before and after RT included lean tissue mass (air-displacement plethysmography), muscle thickness (ultrasound) of elbow, knee, and ankle flexors and extensors, leg and bench press strength, and urinary indicators of cytotoxicity (formaldehyde), myofibrillar protein degradation [3-methylhistidine (3-MH)],and bone resorption [cross-linked N-telopeptides of type I collagen (NTx)]. RESULTS Subjects in C and CP groups combined experienced greater increases in body mass and total muscle thickness than PLA (P < 0.05). Subjects who received CP increased lean tissue mass (+5.6%) more than C (+2.2%) or PLA (+1.0%; P < 0.05) and increased bench press strength (+25%) to a greater extent than C and PLA combined (+12.5%; P < 0.05). CP and C did not differ from PLA for changes in formaldehyde production (+24% each). Subjects receiving creatine (C and CP) experienced a decrease in 3-MH by 40% compared with an increase of 29% for PLA (P < 0.05) and a reduction in NTx (-27%) versus PLA (+13%; P = 0.05). CONCLUSIONS Low-dose creatine combined with protein supplementation increases lean tissue mass and results in a greater relative increase in bench press but not leg press strength. Low-dose creatine reduces muscle protein degradation and bone resorption without increasing formaldehyde production.

Diets supplemented with chickpea or its main oligosaccharide component raffinose modify faecal microbial composition in healthy adults

The effects of diets supplemented with either chickpea or its main oligosaccharide raffinose on the composition of the faecal microbial community were examined in 12 healthy adults (18-65 years) in a randomised crossover intervention study. Subjects consumed their usual diet supplemented with soups and desserts that were unfortified, or fortified with either 200 g/d of canned chickpeas or 5 g/d of raffinose for 3 week periods. Changes in faecal bacterial populations of subjects were examined using 16S rRNA-based terminal restriction fragment length polymorphisms (T-RFLP) and clone libraries generated from the diet pools. Classification of the clone libraries and T-RFLP analysis revealed that Faecalibacterium prausnitzii, reported to be an efficient butyrate producer and a highly metabolically active bacterium in the human intestinal microbiota, was more abundant in the raffinose diet and the chickpea diet compared to the control diet. However, no significant difference was observed in the faecal total short chain fatty acid concentration or in the levels of the components (butyrate, acetate and propionate) with the chickpea diet or the raffinose diet compared to the control diet. Bifidobacterium species were detected by T-RFLP in all three diet groups and quantitative real-time PCR (qPCR) analysis showed a marginal increase in 16S rRNA gene copies of Bifidobacterium with the raffinose diet compared to control (P>0.05). The number of individuals showing TRFs for the Clostridium histolyticum - Clostridum lituseburense groups, which include pathogenic bacteria species and putrefactive bacteria, were lower in the chickpea diet compared to the other two treatments. Diet appeared to affect colonisation by a high ammonia-producing bacterial isolate which was detected in 83%, 92% and 42% of individuals in the control, raffinose and chickpea groups, respectively. Our results indicate that chickpea and raffinose have the potential to modulate the intestinal microbial composition to promote intestinal health in humans.

Digestive and physiologic effects of a wheat bran extract, arabino-xylan-oligosaccharide, in breakfast cereal.

OBJECTIVE We assessed whether a wheat bran extract containing arabino-xylan-oligosaccharide (AXOS) elicited a prebiotic effect and influenced other physiologic parameters when consumed in ready-to-eat cereal at two dose levels. METHODS This double-blind, randomized, controlled, crossover trial evaluated the effects of consuming AXOS at 0 (control), 2.2, or 4.8 g/d as part of ready-to-eat cereal for 3 wk in 55 healthy men and women. Fecal microbial levels, postprandial serum ferulic acid concentrations, and other physiologic parameters were assessed at the beginning and end of each condition. RESULTS The median bifidobacteria content of stool samples (log₁₀/grams of dry weight [DW]) was found to be higher in the subjects consuming the 4.8-g/d dose (10.03) than in those consuming 2.2 g/d (9.93) and control (9.84, P < 0.001). No significant changes in the populations of other fecal microbes were observed, indicating a selective increase in fecal bifidobacteria. Postprandial ferulic acid was measured at 120 min at the start and end of each 3-wk treatment period in subjects at least 50 y old (n = 37) and increased in a dose-dependent manner (end-of-treatment values 0.007, 0.050, and 0.069 μg/mL for the control, AXOS 2.2 g/d, and AXOS 4.8 g/d conditions, respectively, P for trend < 0.001). CONCLUSION These results indicate that AXOS has prebiotic properties, selectively increasing fecal bifidobacteria, and increases postprandial ferulic acid concentrations in a dose-dependent manner in healthy men and women.

Improvement of the representation of bifidobacteria in fecal microbiota metagenomic libraries by application of the cpn60 universal primer cocktail.

ABSTRACT Actinobacteria, particularly bifidobacteria, are widely observed to be underrepresented in metagenomic studies of microbial communities. We have compared human fecal microbiota clone libraries based on 16S rRNA and cpn60 PCR products. Taxonomic profiles were similar except that the cpn60 libraries contained large numbers of bifidobacterial sequences.

D-Lactate altered mitochondrial energy production in rat brain and heart but not liver

BackgroundSubstantially elevated blood D-lactate (DLA) concentrations are associated with neurocardiac toxicity in humans and animals. The neurological symptoms are similar to inherited or acquired abnormalities of pyruvate metabolism. We hypothesized that DLA interferes with mitochondrial utilization of L-lactate and pyruvate in brain and heart.MethodsRespiration rates in rat brain, heart and liver mitochondria were measured using DLA, LLA and pyruvate independently and in combination.ResultsIn brain mitochondria, state 3 respiration was 53% and 75% lower with DLA as substrate when compared with LLA and pyruvate, respectively (p < 0.05). Similarly in heart mitochondria, state 3 respiration was 39% and 86% lower with DLA as substrate when compared with LLA or pyruvate, respectively (p < 0.05). However, state 3 respiration rates were similar between DLA, LLA and pyruvate in liver mitochondria. Combined incubation of DLA with LLA or pyruvate markedly impaired state 3 respiration rates in brain and heart mitochondria (p < 0.05) but not in liver mitochondria. DLA dehydrogenase activities were 61% and 51% lower in brain and heart mitochondria compared to liver, respectively, whereas LLA dehydrogenase activities were similar across all three tissues. An LDH inhibitor blocked state 3 respiration with LLA as substrate in all three tissues. A monocarboxylate transporter inhibitor blocked respiration with all three substrates.ConclusionsDLA was a poor respiratory substrate in brain and heart mitochondria and inhibited LLA and pyruvate usage in these tissues. Further studies are warranted to evaluate whether these findings support, in part, the possible neurological and cardiac toxicity caused by high DLA levels.

Closing the anion gap: Contribution of d-lactate to diabetic ketoacidosis

BACKGROUND A high anion gap in diabetic ketoacidosis (DKA) suggests that some unmeasured anions must contribute to the generation of the anion gap. We investigated the contribution of D-lactate to the anion gap in DKA. METHODS Diabetic patients with and without DKA and high anion gap were recruited. Plasma D-lactate was quantified by HPLC. Plasma methylglyoxal was assayed by liquid chromatography-tandem mass spectrometry. RESULTS The plasma fasting glucose, β-hydroxybutyrate, and blood HbA1c levels were highly elevated in DKA. Plasma anion gap was significantly increased in DKA (20.59±6.37) compared to either the diabetic (7.50±1.88) or the control group (6.53±1.75) (p<0.001, respectively). Moreover, plasma D-lactate levels were markedly increased in DKA (3.82±2.50 mmol/l) compared to the diabetic (0.47±0.55 mmol/l) or the control group (0.25±0.35 mmol/l) (p<0.001, respectively). Regression analysis demonstrated that D-lactate was associated with acidosis and anion gap (r=0.686, p<0.001). CONCLUSIONS Plasma D-lactate levels are highly elevated and associated with metabolic acidosis and the high anion gap in DKA. Laboratory monitoring of d-lactate will provide valuable information for assessment of patients with DKA.

Foods With Added Fiber Lower Serum Creatinine Levels in Patients With Chronic Kidney Disease

OBJECTIVE To determine the effect of foods with added fiber on blood urea nitrogen (BUN) and serum creatinine concentrations in patients with chronic kidney disease (CKD). DESIGN Participants were enrolled in a 6-week single-blind crossover study. SETTING Free living with partial dietary intervention. PATIENTS Thirteen CKD patients with Modification of Diet in Renal Disease formula-based estimated glomerular filtration rate (eGFR) ≤50 mL/minute/1.73 m(2) at the time of screening (5 men, 8 women; mean age, 67.0 ± 14.8 years) completed the study. INTERVENTION Patients consumed control foods (cereal, cookies, and bars) providing 1.6 g/day fiber daily for 2 weeks, followed by similar foods providing 23 g/day fiber daily for 4 weeks, incorporated into their usual diets. MAIN OUTCOME The main outcome of the study was the determination of the impact of foods with added fiber on BUN and serum creatinine levels. RESULTS Consuming foods with added fiber resulted in a 10.6% decrease in mean BUN concentration (13.8 ± 2.0 to 12.1 ± 1.8 mmol/L or 38.5 ± 5.6 to 34.0 ± 5.1 mg/dL; P < .05). Serum creatinine level decreased from a baseline value of 216 ± 26 to 201 ± 23 mmol/L (2.44 ± 0.30 to 2.27 ± 0.26 mg/dL; P < .05) after 2 weeks of fiber-containing food consumption, and remained significantly lower at 195 ± 23 mmol/L (2.21 ± 0.26 mg/dL) after 4 weeks of the intervention (P < .05). Calculated eGFR increased from a baseline value of 29.6 ± 3.5 to 31.4 ± 3.8 mL/minute/1.73 m(2) at the end of 2 weeks, and remained higher at 32.5 ± 3.6 mL/minute/1.73 m(2) after 4 weeks of fiber intervention (P < .05). CONCLUSION We conclude that increasing fiber intake in CKD patients through the consumption of foods with added fiber may reduce serum creatinine levels and improve eGFR. Additional studies are warranted to confirm these findings and to determine whether the changes are due to direct effects on kidney function.

A pulse-based diet is effective for reducing total and LDL-cholesterol in older adults.

Our purpose was to determine the effects of a pulse-based diet in individuals 50 years or older for reducing CVD risk factors. A total of 108 participants were randomised to receive pulse-based foods (two servings daily of beans, chickpeas, peas or lentils; about 150 g/d dry weight) or their regular diet for 2 months, followed by a washout of 1 month and a cross-over to the other diet for 2 months. Anthropometric measures, body composition and biochemical markers (i.e. serum LDL-cholesterol (LDL-C), as the primary outcome, and other lipids, glucose, insulin and C-reactive protein) were assessed before and after each diet phase. A total of eighty-seven participants (thirty males and fifty-seven females; 59·7 (sd 6·3) years, body mass 76 (sd 16) kg) completed the study. Compared with the regular diet, the pulse-based diet decreased total cholesterol by 8·3 % (pulse, 4·57 (sd 0·93) to 4·11 (sd 0·91) mmol/l; regular, 4·47 (sd 0·94) to 4·39 (sd 0·97) mmol/l; P < 0·001) and LDL-C by 7·9 % (pulse, 2·93 (sd 0·84) to 2·55 (sd 0·75) mmol/l; regular, 2·96 (sd 0·86) to 2·81 (sd 0·83) mmol/l; P = 0·01). In a sub-analysis of individuals with high lipid levels at baseline (twenty individuals with high cholesterol), the pulse-based diet reduced cholesterol by 6 % compared with the regular diet (pulse, 5·62 (sd 0·78) to 5·26 (sd 0·68) mmol/l; regular, 5·60 (sd 0·91) to 5·57 (sd 0·85) mmol/l; P = 0·05). A pulse-based diet is effective for reducing total cholesterol and LDL-C in older adults and therefore reduces the risk of CVD.

Short-term heavy resistance training eliminates age-related deficits in muscle mass and strength in healthy older males.

Candow, DG, Chilibeck, PD, Abeysekara, S, and Zello, GA. Short-term heavy resistance training eliminates age-related deficits in muscle mass and strength in healthy older males. J Strength Cond Res 25(2): 326-333, 2011-The objective of this investigation was to determine whether short-term heavy resistance training (RT) in healthy older men could eliminate deficits in muscle mass and strength (ST) compared with healthy younger men. Seventeen older men (60-71 yr) performed supervised RT for 22 weeks. Before and after RT, measurements were made for lean tissue mass (LTM), muscle thickness (MT), and ST (leg and bench press 1 repetition maximum) and were compared with values of younger men (n = 22-60 for the different measures, 18-31 yr). Before training, older men had significantly lower (p < 0.05) LTM (58.4 ± 7.0 kg), MT (3.4 ± 0.7 cm), and ST (leg press = 168 ± 33 kg; bench press = 75 ± 18 kg) compared with younger men (LTM 64.3 ± 7.1 kg; MT 4.0 ± 0.8 cm; leg press = 231 ± 54 kg; bench press = 121 ± 31 kg). All deficits were eliminated after 22 weeks of RT (LTM = 60.5 ± 7.6 kg; MT = 4.0 ± 0.7 cm; leg press = 222 ± 48 kg; bench press = 107 ± 19 kg). Short-term, heavy RT in healthy older men is sufficient to overcome deficits in muscle mass and ST when compared with healthy younger men. The practical application from this research is that healthy older men can be prescribed a whole-body heavy RT program to substantially increase muscle mass and ST to levels similar to young, active individuals.

Serum D-Lactate Concentrations in Cats with Gastrointestinal Disease

BACKGROUND Increased D-lactate concentrations cause neurological signs in humans with gastrointestinal disease. HYPOTHESIS/OBJECTIVES To determine if serum D-lactate concentrations are increased in cats with gastrointestinal disease compared to healthy controls, and if concentrations correlate with specific neurological or gastrointestinal abnormalities. ANIMALS Systematically selected serum samples submitted to the Gastrointestinal Laboratory at Texas A&M University from 100 cats with clinical signs of gastrointestinal disease and abnormal gastrointestinal function tests, and 30 healthy cats. METHODS Case-control study in which serum D- and L-lactate concentrations and retrospective data on clinical signs were compared between 30 healthy cats and 100 cats with gastrointestinal disease. Association of D-lactate concentration with tests of GI dysfunction and neurological signs was evaluated by multivariate linear and logistic regression analyses, respectively. RESULTS All 100 cats had a history of abnormal gastrointestinal signs and abnormal gastrointestinal function test results. Thirty-one cats had definitive or subjective neurological abnormalities. D-lactate concentrations of cats with gastrointestinal disease (median 0.36, range 0.04-8.33 mmol/L) were significantly higher than those in healthy controls (median 0.22, range 0.04-0.87 mmol/L; P = .022). L-lactate concentrations were not significantly different between the 2 groups of cats with gastrointestinal disease and healthy controls. D-lactate concentrations were not significantly associated with fPLI, fTLI, cobalamin, folate, or neurological abnormalities (P > .05). CONCLUSIONS AND CLINICAL IMPORTANCE D-lactate concentrations can be increased in cats with gastrointestinal disease. These findings warrant additional investigations into the role of intestinal microbiota derangements in cats with gastrointestinal disease, and the association of D-lactate and neurological abnormalities.