Effects of exercise in hot and humid conditions and bovine colostrum on salivary immune markers

Does Colostrum Bovinum Supplementation Affect Swimming Performance in Endurance-Trained Males? A Randomized Placebo-Controlled Crossover Study

Background/Objectives: Colostrum Bovinum (COL) is recognized for its unique composition and potential ergogenic and immunological benefits. Unlike mature milk, COL is rich in immunoglobulins, lactoferrin, and various growth factors, making it one of the most potent natural immune stimulants. The purpose of this study was to evaluate the effects of 12-weeks of COL supplementation on swimming-specific performance (SSP) and exercise adaptations in endurance-trained male athletes. Methods: Twenty-eight male triathletes and swimmers (age: 31.1 ± 10.2 years; body mass: 81.9 ± 9.0 kg; height: 1.82 ± 0.06 m) participated in a randomized, double-blind, placebo (PLA)-controlled crossover study and received 25 g∙day-1 of COL or PLA for 12 weeks. The study assessed the effects of COL on SSP (8 × 100 m performed at various intensities) and exercise adaptations [heart rate (HR) and blood lactate concentrations ([La-])]. Four main study visits were conducted-before and after COL (COLPRE and COLPOST) and PLA (PLAPRE and PLAPOST) supplementation. Results: COL had no significant effect on SSP. Still, the total time of the SSP test was about ~3.04 s shorter after COL supplementation, and ~7.13 s longer after PLA supplementation. Neither COL nor PLA supplementation affected HR during the SSP test. Post-exercise blood [La-] was significantly reduced after both COL and PLA supplementation. The analysis of SSP results in the consecutive study visits revealed possible existence of the practice effect. Conclusions: Colostrum Bovinum and high-quality milk protein (PLA) seem to be comparably effective in evoking exercise adaptation in endurance-trained male athletes. Long-term crossover supplementation protocols in athletes must consider the impact of possible practice effect when interpreting the outcomes related to exercise performance, but not biochemical or physiological markers of exercise adaptation.

Effects of Heat-Not-Burn Cigarette Smoking on the Secretion of Saliva and Its Innate Immune System Components

Saliva and salivary antimicrobial proteins play important roles in the innate immunity, which prevents infections of orally invading bacteria and viruses. In this study, we compared the secretion rates of salivary lactoferrin (Lac) and lysozyme (Lys) in heat-not-burn (HNB) cigarette smokers and non-smokers. The analysis population for this study included 212 members of the fire department, including 32 HNB cigarette smokers, 17 paper cigarette smokers, 14 combined HNB and paper cigarette smokers, and 149 non-smokers. Salivary Lac and Lys concentrations were assessed using enzyme immunoassay. Saliva secretion was significantly lower among HNB cigarette smokers (p < 0.01) than among non-smokers. Accompanying this result, salivary Lac and Lys secretion rates were significantly lower among smokers, particularly HNB cigarette smokers, than among non-smokers (all p < 0.01). Our findings suggest a possible adverse effect of HNB cigarette on the amount of Lac and Lys released into the oral cavity.

Effects of caffeinated beverage ingestion on salivary antimicrobial proteins responses to acute exercise in the heat

Caffeine is commonly used by athletes as an energy supplement, but studies on its effects on salivary antimicrobial proteins (sAMPs) in humans during exercise are rare with ambiguous findings. It is also still controversial whether hot environments affect sAMPs. Using a double-blind, randomized crossover design, we examined 12 endurance-trained male collegiate athletes who completed the following two experiments: a caffeine experiment (CAF) and a placebo experiment (PLA). The participants acutely consumed caffeine-containing (6 mg/kg body weight) sports drink (3 ml/kg body weight) or an equivalent amount of placebo sports drink and subsequently performed cycling exercise for 40 min in the heat (33 ± 0.24°C, 64 ± 2.50% relative humidity) at 50% of maximum output power, maintaining a pedal frequency of 60 rpm. Saliva was collected at 60 min pre-exercise (T–60), the start of exercise (T0), 20 min of exercise (T20), and the end of the exercise (T40), and salivary α-amylase (sAA) and lactoferrin (sLac) were tested. The rating of perceived exertion (RPE) was measured at T0–T40, while core body temperature (Tre) and heart rate (HR) were monitored continuously. Tre, HR, and RPE increased with time during the exercise (p &lt; 0.01), with no difference in Tre and HR between the CAF and PLA (p &gt; 0.05), but RPE was higher in the PLA than in the CAF (p &lt; 0.05). sLac concentrations were significantly higher at T20 and T40 than at T–60 (p &lt; 0.01) and higher at T40 than at T0 and T20 (p &lt; 0.01), with no difference between the CAF and PLA (p &gt; 0.05). Compared with T–60, sAA activity was significantly increased at T0, T20, and T40 (p &lt; 0.01). sAA activity was significantly higher at T40 than at T0 and T20 (p &lt; 0.01), at T20 than at T0 (p &lt; 0.05), and in the CAF than in the PLA (p &lt; 0.01). Heat stress caused by acute exercise in hot environments did not impair the sAMPs parameters of the participants. Instead, the participants showed transient increase in sAA activity and unchanged sLac concentrations. Caffeine may increase salivary markers related to immune response during exercise.

Insights into the Research Trends on Bovine Colostrum: Beneficial Health Perspectives with Special Reference to Manufacturing of Functional Foods and Feed Supplements

Bovine colostrum (BC) is the initial mammary secretion after parturition, which is nature's bountiful source consisting of nutritional and bioactive components present in a highly concentrated low-volume format. All mammalian newborns require colostrum to enhance physiological processes such as lifelong immunity, gastrointestinal development, and resistance to microbial infections. The genetic, environmental, and processing methods can all have an impact on the biochemical contents of BC and its supplements. BC and its derivatives have been intensively researched for their potential use in functional foods, medicines, and animal feed. Evidence from clinical studies suggests that BC products are well-tolerated, nontoxic, and safe for human ingestion. Functional foods, feed, and pharmaceutical formulations based on bovine colostrum are playing noteworthy roles in the development of innovative products for promoting health and the prevention of chronic illnesses. This systematic review sheds light on recent research on (a) the effects of processing techniques on BC components, (b) emerging techniques used in the isolation and identification of novel components, (c) BC-based functional foods for human consumption and animal feed supplements, and (d) the role of BC in current drug delivery, as well as future recommendations.