Dear Colleagues,

Food ingredients play a crucial role in human health, and the health-promoting effects of food ingredients are highly related to their digestion and fermentation characteristics in the gastrointestinal tract. A growing amount of evidence suggests that the gut microbiota may serve as an important modulator of the crosstalk between diet and human health. Recently and more strikingly, some reports have demonstrated that some food ingredients, such as polysaccharides and polyphenols, can evade the digestive system without digestion by human enzymes in the saliva, stomach, and small intestine. The indigestible food ingredients can then reach the large intestine intact, where they can be broken down and utilized by gut microbiota. As a result, some health-promoting gut microbiota levels, such as of Akkermansia muciniphila, are increased; furthermore, some beneficial metabolic products such as short-chain fatty acids (SCFAs) in the area are also enhanced, which may positively contribute to human health. Thus, evaluating the digestion and fermentation characteristics of food ingredients is highly important.

It is well-known that it is difficult to detect the changes of food ingredients if an animal model is used to evaluate the digestion and fermentation characteristics of food ingredients due to the complex composition of the animal diet. However, the digestion and fermentation model in vitro have the advantages of reproducibility, simplicity, universality, and can integrally simulate the in vivo conditions to mimic oral, gastric, small intestinal, and large intestinal digestive processes. Thus, the in vitro gastrointestinal digestion and fermentation models have been widely used for evaluating the activities of food ingredients.

Thus, this Special Issue of Fermentation focuses on the in vitro digestibility and ruminal fermentation profile of food ingredients, and it is expected that this publication could substantially expand our knowledge of digestion and fermentation characteristics of food ingredients and further stimulate future research. Accordingly, this Special Issue welcomes experts working in the field to submit original experimental studies and reviews that cover state-of-the-art advances in this important area.

This Special Issue will highlight the most recent advances in, but is not limited to, the following subjects:

• Changes in physicochemical and biological properties during gastrointestinal digestion and fermentation;
• Innovative approaches to evaluating the digestion and fermentation characteristics of food ingredients;
• Metabolic characteristics and biotransformation of food ingredients during gastrointestinal digestion and fermentation system;
• The interaction between gut microbiota and food ingredients;
• The potential risk of food ingredients on the human health evaluated using a digestion and fermentation model in vitro.

Prof. Dr. Guijie Chen
Dr. Zhuqing Dai
Prof. Dr. Chunxu Chen
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Fermentation is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• in vitro digestibility
• ruminal fermentation
• gut microbiota
• multi-omics techniques
• metabolic characteristics and biotransformation
• prebiotic activity
• food ingredients
• health-promoting functions
• potential risk