Stable-isotope labeled plant products

IsoLife produces and sells Stable Isotope labelled (>97 atom %) products derived from food plants for use as Tracers and Internal Standards in a wide range of research areas and diagnostics in the Life Sciences.

Stable isotope probing (SIP)

Safe stable isotope technologies contribute to food innovation by:

• Tracing and identifying fermentation products of ¹³C-labeled dietary fibers in the colon and uptake of ¹³C SCFA’s,
• Identifying the functional gut microbial species involved in e.g. fermentation through stable isotope probing (SIP),
• Measuring bioavailability of bio-active ingredients in the gut system.

Gut microbiota

Innovative food plant products that have been developed include e.g. U-¹³C Starch, U-¹³C Inulin, U-DHA, U-¹³C Tomato, U-¹³C Lycopene, U-¹³C Solanine.

Recently, uniformly ¹³C-labelled starch (>98 atom % ¹³C) was used in a mice study (Herrmann et al., 2017), which showed that resistant starch assimilating bacteria in fecal samples mainly belonged to Bacteroidetes, as well as members of the Ruminococcacea family. These species were able to convert resistant starch into SCFA’s since ¹³C was recovered in acetate, propionate and butyrate.

A similar study with uniformly ¹³C-labeled inulin (>97 atom % ¹³C) has been used in rat studies to elucidate the microflora involved in fermentation processes of dietary fibers (Butts et al., 2016; Tannock et al., 2014). They showed that the presence of inulin in the diet positively influenced large bowel microbial fermentation and that Bacteroides uniformis, Blautia glucerasea, Clostridium indolis, and Bifidobacterium animalis were the main users of the ¹³C inulin and probably the main producers of ¹³C SCFA’s in the bowel.

In a human trial, the effect of wheat bran on the production of SCFA’s after consumption of ¹³C labelled inulin was investigated (Deroover et al, 2017). Fermentation of ¹³C-inulin increased plasma SCFA concentrations, but the addition of a single dose of wheat bran did not further increase the SCFA production.

Frost et al. (2014) used U-¹³C inulin to monitor the accumulation of its fermentation product ¹³C acetate in the hypothalamus of mice by NMR in order to prove their hypothesis that acetate plays a direct role in reducing appetite via a central homeostatic mechanism.

Bioavailability

The availability of unique food tracers like U-¹³C Starch and U-¹³C Inulin appear to be highly beneficial for the power and resolution of food studies.

Links to online publications

Deroover L, J Verspreet, A Luypaerts, G Vandermeulen, CM Courtin, K Verbeke. 2017.
Wheat bran does not affect postprandial plasma short-chain fatty acids from ¹³C-inulin fermentation in healthy subjects.
Nutrients 9: 83.

Herrmann E, W Young, D Rosendale, R Conrad, CU Riedel, M Egert. 2017.
Determination of resistant starch assimilating bacteria in fecal samples of mice by in vitro RNA-based Stable Isotope Probing.
Frontiers in Microbiology 8: 1331.

Butts CA, G Paturi, MH Tavendale, D Hedderley, H Stoklosinski, T Herath, D Rosendale, N Roy, JA Monro, J Ansell. 2016.
The fate of ¹³C-labelled and non-labelled inulin predisposed to large bowel fermentation in rats.
Food and Function 7: 1825-1832.

Frost G, ML Sleeth, M Sahuri-Arisoylu, B Lizarbe, S Cerdan, L Brody, J Anastasovska, S Ghourab, M Hankir, S Zhang, D Carling, JR Swann, G Gibson, A Viardot, D Morrison, EL Thomas, JD Bell. 2014.
The short-chain fatty acid acetate reduces appetite via a central homeostatic mechanism.
Nature Communications 5. DOI: 10.1038/ncomms4611.

Tannock GW, B Lawley, K Munro, IM Sims, J Lee, CA Butts, N Roy. 2014.
RNA-stable isotope probing (RNA-SIP) shows carbon utilization from inulin by specific bacterial populations in the large bowel of rats.
Applied and Environmental Microbiology 80: 2240-2247.