Bile acids and oxo-metabolites as markers of human faecal input in the ancient Pompeii ruins.

Small organic molecules, lipids, proteins, and DNA fragments can remain stable over centuries. Powerful and sensitive chemical analysis can therefore be used to characterize ancient remains for classical archaeological studies. This bio-ecological dimension of archaeology can contribute knowledge about several aspects of ancient life, including social organization, daily habits, nutrition, and food storage. Faecal remains (i.e. coprolites) are particularly interesting in this regard, with scientists seeking to identify new faecal markers. Here, we report the analysis of faecal samples from modern-day humans and faecal samples from a discharge pit on the site of the ruins of ancient Pompeii. We propose that bile acids and their gut microbiota oxo-metabolites are the most specific steroid markers for detecting faecal inputs. This is due to their extreme chemical stability and their exclusive occurrence in vertebrate faeces, compared to other ubiquitous sterols and steroids.

Rapid Ion Mobility Separations of Bile Acid Isomers Using Cyclodextrin Adducts and Structures for Lossless Ion Manipulations.

Bile acids (BAs) constitute an important class of steroid metabolites often displaying changes associated with disease states and other health conditions. Current analyses for these structurally similar compounds are limited by a lack of sensitivity and long separation times with often poor isomeric resolution. To overcome these challenges and provide rapid analyses for the BA isomers, we utilized cyclodextrin adducts in conjunction with novel ion mobility (IM) separation capabilities provided by structures for lossless ion manipulations (SLIM). Cyclodextrin was found to interact with both the tauro- and glyco-conjugated BA isomers studied, forming rigid noncovalent host-guest inclusion complexes. Without the use of cyclodextrin adducts, the BA isomers were found to be nearly identical in their respective mobilities and thus unable to be baseline resolved. Each separation of the cyclodextrin-bile acid host-guest inclusion complex was performed in less than 1 s, providing a much more rapid alternative to current liquid chromatography-based separations. SLIM provided capabilities for the accumulation of larger ion populations and IM peak compression that resulted in much higher resolution separations and increased signal intensities for the BA isomers studied.

Simultaneous assessment of lipid classes and bile acids in human intestinal fluid by solid-phase extraction and HPLC methods.

The purpose of the study reported here was to develop a method for the determination of lipid classes in intestinal fluids, including bile acids (BAs). A solid-phase extraction (SPE) method using C18 and silica columns for the separation of BAs, phospholipids (PLs), and neutral lipids (NLs), including free fatty acids, has been developed and validated. Fed-state small intestinal fluid collected from humans was treated with orlistat to inhibit lipolysis and mixed with acetic acid and methanol before SPE to maximize lipid recoveries. BAs, PLs, and NLs were isolated using lipophilic and polar solvents to promote elution from the SPE columns. The different lipid classes were subsequently analyzed using three separately optimized HPLC methods with evaporative light-scattering detectors. High recoveries (>90%) of all lipids evaluated were observed, with low coefficients of variation (<5%). The HPLC methods developed were highly reproducible and allowed baseline separation of nearly all lipid classes investigated. In conclusion, these methods provide a means of lipid class analysis of NLs, PLs, and BAs in human fed-state small intestinal fluid, with potential use in other fluids from the intestinal tract and animals.

Acidos biliares VII: estudio de factibilidad técnica de utilización de la bilis de chivo para la obtención de ácidos biliares de interés para la industria farmacéutica / Bile acids VII: study of technical feasibility of using goat bile for the attaiment of concerning bile acids for the pharmaceutical industry

Los ácidos biliares son sustancias esteroidales de origen natural muy utilizado por la terapéutica humana. Desde hace algo más de 15 años estas sustancias son producidas a niveles industriales en nuestro país, a partir de bilis bovina. Dado que esta producción se ve limitada por la disponibilidad de la meteria prima, pues se procesa toda la disponible a nivel nacional, el trabajo se encaminó a estudiar la factibilidad técnica de utilizar la bilis de chivo como fuente alternativa de ácidos biliares de interés. Se presentaron los resultados obtenidos, comparándola con los rendimientos establecidos para la bilis bovina, concluyéndose que de la bilis de chivo es posible aislar aproximadamente 34 g de ácido cólico y de 9 a 10 g de ácido coleinico o 93 g de sales biliares de magnesio por litro de bilis de chivo, y cumple este producto con la calidad requerida. Se concluye que la bilis de chivo está apta para ser utilizada en la obtención de ácidos biliares y derivados de interés para la Industria Farmacéutica