Yoast Breadcrumbs in a Bootstrap-based theme

breadcrumbs.php

<?php
function lightseek_breadcrumbs() {
	// Don't show breadcrumbs on the homepage.
	if ( is_front_page() || !function_exists('yoast_breadcrumb') ) return;

  $bread = yoast_breadcrumb('<nav aria-label="breadcrumb" id="breadcrumbs" class="breadcrumb">','</nav>', false);

  // Apply Bootstrap classes to the breadcrumbs
  $bread = str_replace('class="breadcrumb_last"', 'class="breadcrumb_last breadcrumb-item active"', $bread);
  $bread = str_replace('property="v:title"', 'property="v:title" class="breadcrumb-item"', $bread);

  echo $bread;
}