Metabolic and Microbial Characterizations for the Gastrointestinal Digesta of the Zoo Colobus guereza

Case Report

J Bacteriol Mycol. 2021; 8(1): 1162.

Metabolic and Microbial Characterizations for the Gastrointestinal Digesta of the Zoo Colobus guereza

Toyoda A1,2,3,*, Shionome N1, Kohari D1,2,3, Iida S4, Masato H4, Namae N4, Nakamura S5 and Tsukahara T5

1Department of Food and Life Sciences, Ibaraki University, College of Agriculture, Japan

2Tokyo University of Agriculture and Technology, United Graduate School of Agricultural Science, Japan

3Ibaraki University Cooperation between Agriculture and Medical Science (IUCAM), Japan

4Hitachi Kamine Zoo, Japan

5Kyoto Institute of Nutrition & Pathology, Japan

*Corresponding author: Toyoda A, Department of Food and Life Sciences, Ibaraki University, College of Agriculture, 3-21-1 Chuo, Ami-machi, Inashiki, Ibaraki 300-0393, Japan

Received: January 11, 2021; Accepted: February 05, 2021 Published: February 12, 2021


Abyssinian black-and-white colobus (Colobus guereza) inhabits west, central, and east Africa and lives in social groups in the rain forests. Colobus guereza has a unique foregut digestive system similar to that of ruminants and absorbs organic acids, including Short-Chain Fatty Acids (SCFAs), as energy sources derived from microbial fermentation of plant materials in the gastrointestinal tract. In this study, the gastrointestinal metabolic and microbial features of a male Colobus guereza singly housed in a zoo were characterized, and each digesta from each segment of the digestive tract was collected and subjected to biochemical, microbiome, and metagenome analyses. In this case report, high levels of acetate and propionate were observed in the foregut, while a relatively high level of lactate was detected in the small intestine. Moreover, in the hindgut and the feces, acetate was dominant compared to the other SCFAs. SCFAs analysis indicated that Colobus guereza obtains energy via SCFAs, especially acetate, fermentation in the foregut and hindgut. A metagenome analysis revealed that each part of the digestive tract of Colobus guereza has a unique microbiota. Similar to ruminants, Prevotella and Selenomonas were the dominant genera in the foregut, which may indicate microbial fermentation of plant materials in the foregut of Colobus guereza.

Keywords: Colobus Guereza; Gastrointestinal Digesta; Metabolome; Microbiome; Organic Acid


Abyssinian black-and-white colobus (Colobus guereza), one of the major colobine monkeys, inhabits west, central, and east Africa and lives in social groups in the rain forests [1]. A previous study reported that Colobus guereza spends 52-63 % of its time resting and 19-26 % feeding [2] and has an abnormally low basal metabolic rate, which may be linked to their lower activity level [3]. Moreover, they choose valuable food habitats and consume various plant materials, including leaves, seeds, and fruits, depending on their location and the season [4-8]. Colobus guereza consumes mainly leaves and fruits [2]. Therefore, they obtain their dietary energies and nutrients mainly from plant materials, including cellulosic fibers via a foregutfermentation digestive system similar to that of ruminants [9]. The Colobus monkey has a forestomach consisting of three regions, namely the cardiac gland, proper gastric and pyloric gland regions [10]. The cardiac gland region of the stomach is larger than the other regions and provides the environment for microbial fermentation of plant materials. Actually, microbial fermentation in the foregut of the colobus is similar to rumen fermentation in terms of bacterial counts, digestive enzymes, organic acids, and pH [11-14]. Recently, a metagenome analysis of the feces of the colobus was performed using the next-generation sequencing system [15,16]; however, the whole composition of their digestive microbiome is unclear. Colobus guereza is captured and displayed in zoos, and their care manual [17] provide the appropriate and practical information on the nutrients and feeds for zoo Colobuses based on several basic research [7,18-21]. However, knowledge of the microbial and metabolic features of the digestive tracts of zoo Colobuses is limited. In this study, we obtained digesta samples from the zoo Colobus guereza, which died during anesthesia, and elucidated the general digestive features by analyzing the organic acids, metabolome, and metagenome of the digesta.

Case Presentation

Animal and digesta samples

Abyssinian black-and-white colobus (Colobus guereza, male, 7 years old) was singly reared and housed at the Kamine Zoo (Hitachicity, Ibaraki, Japan), and died unexpectedly during anesthesia for a regular health examination. After the post-mortem examination by the veterinarian, the complete gastrointestinal tract was removed and the regions were numbered (Nos.1-12) as shown in (Figure 1A); the digesta was collected immediately from each region and stored at -80 °C until analyses. Before the sampling, Colobus guereza was normally kept in a cage during the daytime and in the next closed bedroom during nighttime. The feed contents for Colobus guereza are shown in (Table S1). Feed was provided three times every day, and water was provided ad libitum. During the daytime, visitors could nearly approach but not directly touch the Colobus guereza in the cage.

Organic acid analysis using ion-exclusion HPLC

Organic acid concentrations in the digesta were measured using ion-exclusion High-Performance Liquid Chromatography (HPLC) as described previously [22]. Organic acids were detected in all the digesta samples, but the digesta from the Pars Pylorica (PP9) had a relatively low concentration of organic acids compared to the digesta from the other regions. Obviously, higher levels of acetate were detected in both the foregut (PS12, TG11, and S10) and the hindgut (C4, PC3, DC2, and R1). Conversely, the concentrations of succinate, formate, and n-valerate were lower than those of acetate and n-butyrate. Furthermore, lactate concentrations were higher in the digesta from the small intestine (D8, PJ7, DJ6, and I5) than the digesta from other regions (Figure 1B, Table S2).

Microbiota analysis using the miseq platform

Bacterial DNA was extracted from the digesta as described previously [23]. The microbiota composition of the digesta was analyzed using Next-Generation Sequencing (NGS) and the MiSeq platform (Illumina, CA, USA) as previously described [24]. The alpha diversity in each gastrointestinal digesta was different: the hindgut digesta showed higher alpha diversity than the forestomach. Weighted UniFrac principal coordinates analysis showed that the forestomach, small intestine, and large intestine had different microbiota. The top 10 abundant genera in the stomach, small intestine, and large intestine are shown in (Table 1), respectively. As shown in (Tables 2), each gastrointestinal digesta had a unique microbiota. In the forestomach (PS12, TG11, and S10), the genera Prevotella and Selenomonas were dominant, while the genus Clostridium was dominant in PP9 (Table 1). In the small intestine, each digesta (D8, PJ7, DJ6, and I5) also had a unique microbiota, the genus Turicibacter was predominant in I5 compared with the other regions (Table 2). In the large intestine, the various digesta (C4, PC3, DC2 and R1) had similar microbiota, relatively the family Ruminococcaceae was dominant (Table 3).