## 1 Introduction  
Aging refers to a progressive decline in biological structures and functions over time, resulting in increased susceptibility to external stress, disease, and mortality risk. Aging detrimentally affects intestinal function, which is closely associated with a multitude of diseases [1]. The intestine, where approximately 70% of immune cells are gathered, has an important relationship with the immune system. It is constantly damaged by mechanical stress, chemical stress (such as carcinogens from the external environment), and biological stress from harmful bacteria [2]. To maintain intestinal homeostasis, a crucial element is the intestinal barrier upheld by the mucus layer. This layer is composed of mucin produced by goblet cells in the intestinal epithelial layer. It plays vital physiological roles in nutrient absorption, promotion of beneficial gut microbiota growth, inhibition of pathogenic bacteria invasion, immune regulation, and maintenance of intestinal homeostasis [3, 4]. Hence, the mucus layer plays a pivotal role in intestinal health. Aging can decrease expression levels of genes associated with intestinal mucus, resulting in decreased thickness of the intestinal mucosa and alterations in gut microbiota compositions [5]. Recent studies have revealed a correlation between aging and reduced diversity within core microbiota groups as well as decreased levels of short-chain fatty acids (SCFAs) [6]. Metabolites such as SCFAs produced by gut microbiota through dietary fiber fermentation are crucial for maintaining gut homeostasis and reducing health risk [7]. In other words, these pieces of evidence indicate the necessity of improving intestinal damage caused by aging to prevent various diseases. Glasswort (_Salicornia herbucea_ L.) is a halophytic plant found in tideland or seashores. It thrives in environments with high salt concentrations. It accumulates a significant amount of salt compared to land plants. Glasswort has been reported to contain high contents of dietary fibers, phytochemicals, and minerals such as magnesium, calcium, potassium, and iron [8]. Recently, an imbalanced diet has led to a deficiency in micronutrients such as iron, zinc, and minerals in a global population of two billion individuals. This micronutrient deficiency has been observed to have adverse effects on physiological functions throughout all age groups, ranging from young children to the elderly [9]. Recent studies have also shown that micronutrient deficiency can significantly impact human gut microbiota [10], contribute to DNA damage, accelerate aging, and increase cancer risk [11]. Furthermore, phytochemicals such as polyphenols and carotenoids are known to provide various physiological benefits including anti-inflammation [12], cardiovascular disease-preventing [13], and anti-cancer [14] effects. Several studies have demonstrated that phytochemicals can modulate gut microbiota compositions, thereby improving gut-related disorders such as inflammatory bowel disease (IBD) [15]. Glasswort contains dicaffeoylquinic acid derivatives and flavonoid glucoside known to exhibit high antioxidative activities [16]. Moreover, glasswort has various biological effects including antioxidant properties [17], anti-cancer activity, anti-obesity effects [18], and immunomodulatory activity [19]. Thus, glasswort could be used as a supplement for minerals and phytochemicals. Fermented foods are associated with a wide range of health benefits. Moreover, the fermentation process can enhance the bioavailability of nutrients and phytochemicals present in these foods [20]. Fermentation process involves lysis of glycosides by microorganisms, resulting in production of aglycones. These aglycones possess diverse physiological functions. They may potentially contribute to health benefits [21]. Recent clinical studies have indicated that fermented foods can reduce the risk of inflammatory diseases and significantly impact gut microbiome compositions [22; 23].