PurposeThere is considerable interest in the effects of the intestinal microbiota (IM) composition, its activities in relation with the metabolism of dietary substrates and the impact these effects may have in the development and prevention of certain non-communicable diseases. It is acknowledged that a complex interdependence exists between the IM and the mammalian host and that the IM possesses a far greater diversity of genes and repertoire of metabolic and enzymatic capabilities than their hosts. However, full knowledge of the metabolic activities and interactions of the IM and the functional redundancy that may exist are lacking. Thus, the current review aims to assess recent literature relating to the role played by the IM in the absorption and metabolism of key nutrients and non-nutrients.MethodsA systematic review (PROSPERO registration: CRD42015019087) was carried out focussing on energy and the following candidate dietary substrates: protein, carbohydrate, fat, fibre, resistant starch (RS), and polyphenols to further understand the effect of the IM on the dietary substrates and the resulting by-products and host impacts. Particular attention was paid to the characterisation of the IM which are predominantly implicated in each case, changes in metabolites, and indirect markers and any potential impacts on the host.ResultsStudies show that the IM plays a key role in the metabolism of the substrates studied. However, with the exception of studies focusing on fibre and polyphenols, there have been relatively few recent human studies specifically evaluating microbial metabolism. In addition, comparison of the effects of the IM across studies was difficult due to lack of specific analysis/description of the bacteria involved. Considerable animal-derived data exist, but experience suggests that care must be taken when extrapolating these results to humans. Nevertheless, it appears that the IM plays a role in energy homeostasis and that protein microbial breakdown and fermentation produced ammonia, amines, phenols and branch chain fatty acids, and a greater diversity in the microbes present. Few recent studies appear to have evaluated the effect of the IM composition and metabolism per se in relation with digestible dietary carbohydrate or fat in humans. Intakes of RS and prebiotics altered levels of specific taxa that selectively metabolised specific prebiotic/carbohydrate-type substances and levels of bifidobacteria and lactobacilli were observed to increase. In controlled human studies, consistent data exist that show a correlation between the intake of fibre and an increase in bifidobacteria and short-chain fatty acids, in particular butyrate, which leads to lower intestinal pH. Dietary polyphenols rely on modification either by host digestive enzymes or those derived from the IM for absorption to occur. In the polyphenol-related studies, a large amount of inter-individual variation was observed in the microbial metabolism and absorption of certain polyphenols.ConclusionsThe systematic review demonstrates t...

Fossil‐based plastic materials are an integral part of modern life. In food packaging, plastics have a highly important function in preserving food quality and safety, ensuring adequate shelf life, and thereby contributing to limiting food waste. Meanwhile, the global stream of plastics into the oceans is increasing exponentially, triggering worldwide concerns for the environment. There is an urgent need to reduce the environmental impacts of packaging waste, a matter raising increasing consumer awareness. Shifting part of the focus toward packaging materials from renewable resources is one promising strategy. This review provides an overview of the status and future of biobased and biodegradable films used for food packaging applications, highlighting the effects on food shelf life and quality. Potentials, limitations, and promising modifications of selected synthetic biopolymers; polylactic acid, polybutylene succinate, and polyhydroxyalkanoate; and natural biopolymers such as cellulose, starch, chitosan, alginate, gelatine, whey, and soy protein are discussed. Further, this review provides insight into the connection between biobased packaging materials and innovative technologies such as high pressure, cold plasma, microwave, ultrasound, and ultraviolet light. The potential for utilizing such technologies to improve biomaterial barrier and mechanical properties as well as to aid in improving overall shelf life for the packaging system by in‐pack processing is elaborated on.

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