Cyclophosphamide (cy) is a widely used cancer drug. Many researchers have focused on the prevention and alleviation of its side effects, particularly damage to the intestinal mucosal barrier. In this study, we examined the effects of fucoidan, isolated from Acaudina molpadioides, on mice with intestinal mucosal damage induced by cyclophosphamide. Our results showed that fucoidan intervention could relieve injury such as decreasing inflammation and increasing the expression of tight junction proteins, and 50 kDa fucoidan significantly increased the abundance of short chain fatty acid (SCFA) producer Coprococcus, Rikenella, and Butyricicoccus (p < 0.05, p < 0.001, and p < 0.05, respectively) species within the intestinal mucosa compared with the cyclophosphamide group, as determined by 16S rDNA gene high-throughput sequencing. In addition, SCFAs, particularly propionate, butyrate, and total SCFAs, were increased in the feces, and SCFA receptors were upregulated in the small intestine. The protective effects of fucoidan on cyclophosphamide treatment may be associated with gut microflora, and 50 kDa fucoidan had superior effects. Therefore, fucoidan may have applications as an effective supplement to protect against intestinal mucosal barrier damage during chemotherapy.

Food additives, often used to guarantee the texture, shelf‐life, taste, and appearance of processed foods, have gained widespread attention due to their increased link to the growing incidence of chronic diseases. As one of the most common additives, carrageenans have been used in human diets for hundreds of years. While classified as generally recognized as safe (GRAS) for human consumption, numerous studies since the 1980s have suggested that carrageenans, particularly those with random coil conformations, may have adverse effects on gastrointestinal health, including aggravating intestinal inflammation. While these studies have provided some evidence of adverse effects, the topic is still controversial. Some have suggested that the negative consequence of the consumption of carrageenans may be structure dependent. Furthermore, pre‐existing conditions may predispose individuals to varied outcomes of carrageenan intake. In this review, structure–function relationships of various carrageenans in the context of food safety are discussed. We reviewed the molecular mechanisms by which carrageenans exert their biological effects. We summarized the findings associated with carrageenan intake in animal models and clinical trials. Moreover, we examined the interactions between carrageenans and the gut microbiome in the pathogenesis of gastrointestinal disorders. This review argues for personalized guidance on carrageenan intake based on individuals’ health status. Future research efforts that aim to close the knowledge gap on the effect of low‐dose and chronic carrageenan intake as well as interactions among food additives should be conducive to the improved safety profile of carrageenans in processed food products.

Stress exposure can increase the appearance of intestinal dysfunction. DHA and EPA have been shown to possess significant anti-inflammatory and immuno-enhancement bioactivities. The aim of the study was to investigate whether different forms of DHA or EPA would affect intestinal barriers (including intestinal epithelium integrity and immunity responses, gut microbiota and its metabolites) in mice under chronic stress, and might therefore prevent stress induced intestinal dysfunction. Chronic stress caused a series of anomalies in the intestine, including decreased faecal water content, increased pro-inflammatory cytokines (IFN-γ, TNF-α, IL-1β and IL-6), reduced expression levels of ZO-1, occludin and E-cadherin, and aberrant microbiota composition (especially Roseburia spp., Prevotella spp., bifidobacteria and lactobacilli) and its metabolites, mainly LPS, acetic acid, propionic acid and butyric acid. Our data indicated that both DHA-PL and EPA-PL counteracted these adverse effects effectively. In conclusion, DHA-PL and EPA-PL may effectively protect mice against intestinal dysfunction under chronic stress exposure as potential ingredients for functional food.

Mucositis is a common problem that results from cancer chemotherapy and is a cause of significant morbidity and occasional mortality. Its prevention and successful treatment can significantly enhance the quality of life of patients and improve their survival. Sea cucumber is a traditional aquatic food that has both nutritional and medicinal value. The polysaccharide fucoidan from the sea cucumber (SC-FUC) has various bioactivities. We examined the protective effect of different molecular weights (MWs 50 kDa–500 kDa) of fucoidan from the sea cucumber, Acaudina molpadioides, in a mouse model of cyclophosphamide (Cy)-induced intestinal mucositis. Results showed that the oral administration of SC-FUC markedly reversed Cy-induced damage in the mice. The sea cucumber fucoidan notably increased the ratio of the length of the intestinal villus to the crypt depth and ameliorated the IFN-γ/IL-4 ratio that signifies Th1/Th2 immune balance. Moreover, all the fucoidans in this study enhanced the expression of IgA by accelerating the expression of IL-6 that is probably combined with IL-10. The differing effects of the varied molecular weights of fucoidan may be due to the difference in the efficiency of absorption. This is a novel study on the potential preventive effects of SC-FUC on intestinal mucositis that may be related to the efficiency of its absorption during digestion. Sea cucumber fucoidan (SC-FUC) may be used as a potential food supplement to prevent chemotherapeutic mucositis.