Metagenomic analysis reveals hidden links between gut microbes and habitat adaptation among cave and surface dwelling Sinocyclocheilus species.

Intestinal microbes are closely related to vital host functions such as digestion and nutrient absorption, which play important roles in enhancing host adaptability. As a natural "laboratory", caves provide an outstanding model for understanding the significance of gut microbes and feeding habits in the habitat adaptability of hosts. However, research on the relationship between gut microbes, feeding habits, and the adaptability of troglobites remains insufficient. In this study, we compared the characteristics of the intestinal microbes of Sinocyclocheilus cavefish and surface fish and further established the relationship between intestinal and habitat microbes. Furthermore, we conducted environmental DNA (eDNA) (metabarcoding) analysis of environmental samples to clarify the composition of potential food resources in the habitats of the Sinocyclocheilus cavefish and surface fish. Results showed that the structure of the Sinocyclocheilus gut microbes was more related to ecological type (habitat type) than phylogenetic relationships. While horizontal transfer of habitat microbes was a source of gut microbes, hosts also showed strong selection for inherent microbes as dominant microorganisms. Differences in the composition and structure of gut microbes, especially dominant microbes, may enhance the adaptability of the two Sinocyclocheilus fish types from the perspectives of food intake, nutrient utilization, and harmful substance metabolism, suggesting that food resources, predation patterns, intestinal flora, digestive and absorptive capacity, and feeding habits and preferences are linked to habitat adaptability. These results should facilitate our understanding of the significance of fish gut microbes to habitat adaptation and provide a new perspective for studying the adaptive mechanisms of cavefish.

Use of pedicled latissimus dorsi myocutaneous flap to reconstruct the upper limb with large soft tissue defects.

OBJECTIVE: To report the technique of reconstruction of large skin and soft tissue defects in the upper extremity using pedicled latissimus dorsi myocu-taneous flaps. METHODS: Six patients with large skin and soft tissue defects were included in this report. There were 5 trauma patients and the rest one needed to receive plastic surgery for his extremity scar. All wounds were in the upper extremity. The sizes of defects ranged from 15 cm multiply 6 cm to 30 cm multiply 18 cm. Pedicled latissimus dorsi myocutaneous flaps were designed according to the defect area and raised with part of latissimus dorsi. The thoracodorsal artery and its perforators were carefully protected during surgery. RESULTS: All flaps healed primarily without flap congestion, margin necrosis or infection. The skin donor sites either received split-thickness skin graft (3 cases, mostly from the anterior thigh) or was closed primarily (3 cases) and had minimal morbidity. Follow-up of 6-12 months showed that the contour of flap was aesthetic and the function of limb was excellent. CONCLUSION: Our experience indicates that the pedicled latissimus dorsi myocutaneous flap is favorable for reconstruction of large skin and soft tissue defects in the upper extremity.

Use of pedicled latissimus dorsi myocutaneous flap to reconstruct the upper limb with large soft tissue defects / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To report the technique of reconstruction of large skin and soft tissue defects in the upper extremity using pedicled latissimus dorsi myocu-taneous flaps.</p><p><b>METHODS</b>Six patients with large skin and soft tissue defects were included in this report. There were 5 trauma patients and the rest one needed to receive plastic surgery for his extremity scar. All wounds were in the upper extremity. The sizes of defects ranged from 15 cm multiply 6 cm to 30 cm multiply 18 cm. Pedicled latissimus dorsi myocutaneous flaps were designed according to the defect area and raised with part of latissimus dorsi. The thoracodorsal artery and its perforators were carefully protected during surgery.</p><p><b>RESULTS</b>All flaps healed primarily without flap congestion, margin necrosis or infection. The skin donor sites either received split-thickness skin graft (3 cases, mostly from the anterior thigh) or was closed primarily (3 cases) and had minimal morbidity. Follow-up of 6-12 months showed that the contour of flap was aesthetic and the function of limb was excellent.</p><p><b>CONCLUSION</b>Our experience indicates that the pedicled latissimus dorsi myocutaneous flap is favorable for reconstruction of large skin and soft tissue defects in the upper extremity.</p>