Microbiota Profiles in Newly Married Couples: Potential Effects on Vision, Sleep and Psychometric Parameters

Overview

Oral, fecal and conjunctival samples will be collected from participants and will be stored (at - 20 and - 80 ◦C) until further processing. On Day 1 and Day 2, all couples will participate in an oral, conjunctival and gut microbiota composition study. Optometry examinations will be completed for each participant Three and Six months later, oral, conjunctival and gut microbiota composition will be analyzed again with the same protocol. The participants will complete a validated Persian version of Pittsburgh Sleep Quality Inventory (PSQI), Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), global sleep assessment questionnaire (GSAQ) and Ocular Surface Disease Index. Consecutive couples will undergo a standard ophthalmology exam and specific assessments for dry eye, including non-anesthetic Schirmer's test and fluorescein tear break-up time on Day 1 and Day 90.

The metabolic activity, diversity and composition of the gut microbiota vary significantly between healthy individuals and insomniacs, and also between hypersomniacs and healthy people. While Clostridiales and Bacteroides are regarded to be the two most important biomarkers for differentiating between healthy people and insomniacs, a recent study demonstrated that an enhanced relative abundance of five genera including Lachnospiraceae UCG010, Hungatella, Collinsella, Gordonibacter and Blautia may be correlated with a diminished risk of some types of hypersomnia (narcolepsy type one). Contrarily, an enhanced relative abundance of class Betaproteobacteria, genus Ruminiclostridium and genus Alloprevotella may potentially increase the risk of narcolepsy type one. Furthermore, recent studies demonstrated that there were no significant differences in alpha and beta diversity between the three groups nonmyopes (NM), progressive myopes (progressive myopes ) and stable myopes (SM). Nothwithstanding, the distributions of Dorea, Roseburia,, Faecalibacterium, Coprococcus, Bacteroides, Bifidobacterium, Megamonas, and Blautia were significantly higher in the myopes (SM and PM combined) when compared with emmetropes. The myopes showed significantly higher abundance of bacteria that are linked to the regulation of dopaminergic signalling, such as Bacteroides, Ruminococcus, Clostridium, Bifidobacterium. Participants with stable myopia were found to have a significantly higher proportion of Prevotella copri than those with progressive myopia. Bifidobacterium adolescentis, a gamma-aminobutyric acid (GABA)-producing bacterium, was significantly higher in all myopes than in NM and, in the comparison between SM and PM, it is significantly higher in SM. B. uniformis and B. fragilis, both GABA-producing Bacteroides, were present in relatively high abundance in all myopes and in SM compared with PM, respectively. Some researches have detected substantial bacterial strain sharing across people with distinct intra-population, mother-to-infant and intra-household transmission patterns. There was considerable strain sharing among cohabiting people, with 32% and 12% median strain-sharing rates for the time since cohabitation and gut and oral microbiomes affected strain sharing more than genetics or age did. Salivary samples were collected from all participant. Couples were instructed not to consume any food or drink, except water, for at least 30 min prior to sample collection. Saliva cortisol was then measured by LC-MS/MS as described before. The validated Persian version Beck Depression Inventory-II (BDI-II), Beck Anxiety Inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI) will be employed to measure depression, anxiety, and sleep quality, respectively. Insomnia in this study is defined as coexistence of both daytime dysfunction and difficulty resuming sleep. Hypersomnia is defined by a bed-rest total sleep time ≥19 hours during the 32-hour recording. SPSS software will be used to analyze the data. Based on these premises, below hypotheses are proposed: * Person-to-person bacterial transmission can change the sleep pattern in newly married couples through gut microbiota * Person-to-person bacterial transmission can alter vision status in newly married couples through ocular microbiota * Person-to-person bacterial transmission can alter depression and anxiety status in newly married couples through ocular microbiota