Intake of Lactobacillus rhamnosus GG (LGG) fermented milk before drinking alcohol reduces acetaldehyde levels and duration of flushing in drinkers with wild-type and heterozygous mutant ALDH2: a randomized, blinded crossover controlled trial.

Alcohol consumption leads to acetaldehyde accumulation, especially in people with mutant aldehyde dehydrogenase 2 gene (ALDH2). Novel strategies to promote acetaldehyde detoxification are required to prevent alcohol-related toxicity. Probiotic bacteria such as Lactobacillus rhamnosus GG (LGG) were shown to have in vitro capacity to detoxify acetaldehyde. This randomized, blinded, placebo-controlled cross-over trial investigated the effect of LGG fermented milk in people with ALDH2 polymorphisms after moderate alcohol intake. Ten healthy wild-type and ten heterozygous mutant ALDH2 Thai men were block randomized into two groups. Each group consumed a different sequence of 150 mL fermented milk containing 108 CFU mL-1 LGG and lactic-acidified milk (placebo), followed by five glasses of beer (0.4 g ethanol per kg body weight), with a one-week wash-out. Consuming LGG fermented milk before alcohol reduced areas under the response curves of blood and salivary acetaldehyde in wild-type and heterozygous mutant ALDH2 individuals (p < 0.05 and p < 0.01, respectively). Interestingly, participants with mutant ALDH2 responded better than wild-type participants for salivary acetaldehyde (90% vs. 70%, p < 0.001). Their durations of flushing were reduced when consuming LGG milk. Regardless of ALDH2 status, 105 CFU mL-1 LGG was retained in saliva at least 3.5 h after milk consumption. In conclusion, intake of LGG fermented milk before drinking alcohol reduces blood and salivary acetaldehyde levels and duration of flushing in drinkers with wild-type and heterozygous mutant ALDH2. The addition of exogenous capacity to detoxify acetaldehyde using the probiotic product could be a potential strategy to promote the alleviation of exposure to reactive and carcinogenic acetaldehyde associated with alcohol drinking in individuals with defective ALDH2 enzyme.

The Effect of Steaming and Fermentation on Nutritive Values, Antioxidant Activities, and Inhibitory Properties of Tea Leaves.

Fermented tea (Cha-miang in Thai) is a local product made by traditional food preservation processes in Northern Thailand that involve steaming fresh tea leaves followed by fermenting in the dark. Information on changes in nutritive values, bioactive compounds, antioxidant activities, and health properties that occur during the steaming and fermenting processes of tea leaves is, however, limited. Changes in nutritive values, phenolics, antioxidant activities, and in vitro health properties through inhibition of key enzymes that control obesity (lipase), diabetes (α-amylase and α-glucosidase), hypertension (angiotensin-converting enzyme (ACE)), and Alzheimer's disease (cholinesterases (ChEs) and ß-secretase (BACE-1)) of fermented tea were compared to the corresponding fresh and steamed tea leaves. Results showed that energy, carbohydrate, and vitamin B1 increased after steaming, while most nutrients including protein, dietary fiber, vitamins (B2, B3, and C), and minerals (Na, K, Ca, Mg, Fe, and Zn) decreased after the steaming process. After fermentation, energy, fat, sodium, potassium, and iron contents increased, while calcium and vitamins (B1, B2, B3, and C) decreased compared to steamed tea leaves. However, the contents of vitamin B1 and iron were insignificantly different between fresh and fermented tea leaves. Five flavonoids (quercetin, kaempferol, cyanidin, myricetin, and apigenin) and three phenolic acids (gallic acid, caffeic acid, and p-coumaric acid) were identified in the tea samples. Total phenolic content (TPC) and antioxidant activities increased significantly after steaming and fermentation, suggesting structural changes in bioactive compounds during these processes. Steamed tea exhibited high inhibition against lipase, α-amylase, and α-glucosidase, while fermented tea possessed high anti-ChE and anti-ACE activities. Fresh tea exhibited high BACE-1 inhibitory activity. Results suggest that tea preparations (steaming and fermentation) play a significant role in the amounts of nutrients and bioactive compounds, which, in turn, affect the in vitro health properties. Knowledge gained from this research will support future investigations on in vivo health properties of fermented tea, as well as promote future food development of fermented tea as a healthy food.