As a measure of stool consistency, faecal dry/wet weight is often a relevant parameter; for example it is one of the main outcomes in our E. coli challenge studies. In addition, we focus on faecal markers of infection, inflammation and immune function, e.g. alpha-1-antitrypsin, beta-defensins, calprotectin, lipocalin, neopterin, elastase, myeloperoxidase, total sIgA (all ELISA). In blood, markers such as circulating antibodies, cytokines/chemokines or C-reactive protein can be analysed. New assays can be developed and validated as required. Markers of gut barrier function include sugars in urine (e.g. lactulose, mannitol, sucrose, sucralose; assessed by HPIC), and faecal mucins (fluorimetric assay).
Clinical studies are essential in providing insights into mechanisms of action of ingredients, and obtaining evidence for efficacy in maintaining optimal health, or in prevention or treatment of diseases. In addition to clinical outcomes, a lot of the information from clinical studies is obtained by the analysis of biological samples, collected from the study participants. At NIZO, we have in-house analytical support for a large range of biomarkers.
Our bioanalytical services can be part of a clinical study, designed and executed by NIZO, but they can also be offered as a stand-alone service for samples that our customers have collected in their own clinical studies. Such studies can take place all over the world, in which case we can also take care of the logistics of sample shipment from different clinical sites to NIZO. The samples in which biomarkers can be analysed range from blood to saliva, nasal lavage, urine and fecal material. Our specialty is analysing stool samples, and we have analysed thousands of samples over the years.
Gut health and immunity
Microbial communities in the gut, but also in the oral and nasal cavity, on the skin, or in the vagina, are increasingly being shown to play an important role in maintenance of health, and in the susceptibility of individuals to certain diseases. At NIZO, we have long-standing experience in the characterization of such microbial communities and their functionalities, as well as in the analysis of fermentation products such as short-chain fatty acids. Integration of microbiome profiling and metagenomics, clinical and biomarker data, with the use of a dedicated bioinformatics pipeline, can be applied to elucidate the role of the microbiome in specific health domains.
In relation to innovations in dairy and plant proteins, digestibility is an important issue. In addition to our in vitro digestion models, we perform studies in healthy volunteers to analyse postprandial kinetics of serum amino acids. Individual serum amino acids are determined in house, e.g. by LC-MS. Nutrient kinetics depend to a large extent on gastric emptying rate. An indication of differences in gastric behaviour of products can be obtained in vitro, but also by analysing stable isotopes in breath samples collected from healthy volunteers after product ingestion.