Alterations in faecal microbiome and resistome in Chinese international travellers: a metagenomic analysis.

BACKGROUND: International travel increases the risk of acquisition of antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). Previous studies have characterized the changes in the gut microbiome and resistome of Western travellers; however, information on non-Western populations and the effects of travel-related risk factors on the gut microbiome and resistome remains limited. METHODS: We conducted a prospective observational study on a cohort of 90 healthy Chinese adult residents of Hong Kong. We characterized the microbiome and resistome in stools collected from the subjects before and after travelling to diverse international locations using shotgun metagenomic sequencing and examined their associations with travel-related variables. RESULTS: Our results showed that travel neither significantly changed the taxonomic composition of the faecal microbiota nor altered the alpha (Shannon) or beta diversity of the faecal microbiome or resistome. However, travel significantly increased the number of ARGs. Ten ARGs, including aadA, TEM, mgrB, mphA, qnrS9 and tetR, were significantly enriched in relative abundance after travel, eight of which were detected in metagenomic bins belonging to Escherichia/Shigella flexneri in the post-trip samples. In sum, 30 ARGs significantly increased in prevalence after travel, with the largest changes observed in tetD and a few qnrS variants (qnrS9, qnrS and qnrS8). We found that travel to low- or middle-income countries, or Africa or Southeast Asia, increased the number of ARG subtypes, whereas travel to low- or middle-income countries and the use of alcohol-based hand sanitizer (ABHS) or doxycycline as antimalarial prophylaxis during travel resulted in increased changes in the beta diversity of the faecal resistome. CONCLUSIONS: Our study highlights travel to low- or middle-income countries, Africa or Southeast Asia, a long travel duration, or the use of ABHS or doxycycline as antimalarial prophylaxis as important risk factors for the acquisition/enrichment of ARGs during international travel.

Does guasha offer hepatoprotective effect to chronic inactive hepatitis B carriers? A built-in design to control subject expectation.

BACKGROUND: A previous case study showed that Guasha, an ancient manual therapeutic technique, could exert hepatoprotective effect in a human chronic active hepatitis B carrier (active-CHB) by modulating the liver enzymes, cytokines, and heme oxygenase-1 (HO-1). The present study serves as a control to the aforementioned case report. The controls were chronic inactive carriers (inactive-CHB) and noncarriers of hepatitis B (NCs). Besides showing a difference in biochemical markers between controls and the previously reported active-CHB case, the asymptomatic condition in both inactive- and active-CHB offers an excellent control for the patient's expectation about Guasha's efficacy. The purpose of this case study was to investigate whether hepatoprotective biochemical markers previously measured in active-CHB in response to Guasha were also present in controls. PARTICIPANTS AND METHODS: Four inactive-CHB and nine NC participants were included. Each participant received a 15-minute Guasha treatment. Blood samples were obtained immediately before Guasha (day 0) and after Guasha (days 2, 5, and 7). Biochemistry values for liver function, HO-1, and T-helper (Th) cytokines were determined from blood tests. Neither the participants nor the investigator who administered Guasha were aware of the blood test results until after all data were collected for all participants. RESULTS: In both inactive-CHB and NC participants, liver function, serum HO-1, and Th1/Th2 cytokines did not significantly differ before and after Guasha. CONCLUSIONS: In contrast to results in active-CHB patients, Guasha did not induce any significant modulation of liver enzymes, HO-1, or cytokines in inactive-CHB and NC participants. The current results suggest that a Guasha-induced hepatoprotective effect depends on the inflammatory event or clinical stage of chronic hepatitis B. Because both active and inactive carriers were completely unaware of their liver status at the time of receiving Guasha, the research protocol is effective in discounting the model that attributes the Guasha therapeutic efficacy to a placebo effect due to participants' expectations.

Guasha-induced hepatoprotection in chronic active hepatitis B: a case study.

BACKGROUND: Heme oxygenase-1 (HO-1) has demonstrated hepatoprotective effect in animal hepatitis models. HO-1 was also reported to be upregulated with Guasha, an ancient therapeutic technique which applies instrument assisted press-stroking to treat many disorders. METHODS: We report a case on the changes of liver function, plasma HO-1 and T-helper (Th) cytokine balance in a chronic active hepatitis B carrier before and after Guasha. The patient presented with increased activities of liver enzymes (ALT and AST), indicating inflammatory damage in liver before Guasha. RESULTS: Forty-eight hours after receiving Guasha, the patient showed changes in a number of serum markers: a decline of liver enzymes (ALT and AST) indicating reduced chronic inflammation, an elevated plasma HO-1, and a modulation of T-helper (Th)1/Th2 balance. CONCLUSIONS: Guasha was shown to transiently reduce the inflammatory markers of liver injury in human, together with an enhancement of HO-1 which might be responsible for the hepatoprotective action.